Systems and methods for controlling an x-ray tube filament

ABSTRACT

This application disclosures a method for calibrating filament current data of an X-ray tube. The method includes obtaining a first value of tube current to be calibrated and a value of filament current to be calibrated, the tube current to be calibrated and the filament current to be calibrated corresponding to a first calibration point; performing an emission operation based on the first value of the tube current to be calibrated and the value of the filament current to be calibrated; determining an actual value of the tube current during the emission operation; determining a difference between the actual value of the tube current and the first value of the tube current to be calibrated; and calibrating, based on the difference, the first calibration point.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/134,552, filed on Dec. 28, 2020, which is a continuation of U.S.patent application Ser. No. 15/798,568 (issued as U.S. Pat. No.10,874,372), filed on Oct. 31, 2017, which is a continuation ofInternational Application No. PCT/CN2017/074306, filed on Feb. 21, 2017,which claims priority of Chinese Application No. CN201610096480.5 filedon Feb. 22, 2016. The disclosures of the above-referenced applicationsare expressly incorporated herein by reference in their entirety.

TECHNICAL FIELD

This application relates to medical imaging, and more particularly,relates to systems and methods for controlling an X-ray tube filament ofthe medical imaging device.

BACKGROUND

A computed tomography (CT) device has a wide range of applications inthe field of medical imaging. In a CT imaging process, an X-ray tube canbe used for emission. Since the density of different tissues isdifferent and the absorption degree of different tissues to X-ray isdifferent, the CT device can complete the image of human tissues. Indifferent CT scanning scenes, the operating parameters of a single X-raytube filament (e.g., filament preheating current, preheating time) maycause the filament temperature to be too high or too low, and thereforecannot meet imaging requirements of different CT scans. Implementingcalibration of the X-ray tube filament accurately and efficiently isstill a difficulty at this stage. Therefore, systems and methods areneeded to solve the above problem.

SUMMARY

This application discloses systems and methods for X-ray tube filamentcontrol.

According to one aspect of the present disclosure, a method forcalibrating filament current data of an X-ray tube is provided. Themethod may include obtaining a first value of tube current to becalibrated and a value of filament current to be calibrated, the tubecurrent to be calibrated and the filament current to be calibratedcorresponding to a first calibration point; performing an emissionoperation based on the first value of the tube current to be calibratedand the value of the filament current to be calibrated; determining anactual value of the tube current during the emission operation;determining a difference between the actual value of the tube currentand the first value of the tube current to be calibrated; andcalibrating, based on the difference, the first calibration point.

According to another aspect of the present disclosure, a system forcalibrating filament current data of an X-ray tube is provided. Thesystem may include a calibration module and a preheating module. Thecalibration module may be configured to obtain a first value of tubecurrent to be calibrated and a value of filament current to becalibrated, the tube current to be calibrated and the filament currentto be calibrated corresponding to a first calibration point; perform anemission operation based on the first value of the tube current to becalibrated and the value of the filament current to be calibrated;determine an actual value of the tube current during the emissionoperation; determine a difference between the actual value of the tubecurrent and the first value of the tube current to be calibrated; andcalibrate, based on the difference, the first calibration point.

According to another aspect of the present disclosure, a non-transitorycomputer readable medium is provided, including executable instructionsthat, when executed by at least one processor, cause the at least oneprocessor to effectuate a method. The method may include calibratingfilament current data of an X-ray tube. The method may include obtaininga first value of tube current to be calibrated and a value of filamentcurrent to be calibrated, the tube current to be calibrated and thefilament current to be calibrated corresponding to a first calibrationpoint; performing an emission operation based on the first value of thetube current to be calibrated and the value of the filament current tobe calibrated; determining an actual value of the tube current duringthe emission operation; determining a difference between the actualvalue of the tube current and the first value of the tube current to becalibrated; and calibrating, based on the difference, the firstcalibration point.

In some embodiments, calibrating, based on the difference, the firstcalibration point may include determining whether the difference issatisfied with a preset condition; and generating, if the difference issatisfied with the preset condition, filament current calibration datacorresponding to the first calibration point.

In some embodiments, determining whether the difference is satisfiedwith the preset condition may include determining whether the differenceis larger than a first threshold and smaller than a second threshold.

In some embodiments, calibrating, based on the difference, the firstcalibration point may further include if the difference is not satisfiedwith the preset condition, updating the first value of the tube currentto be calibrated with the actual value of the tube current, andgenerating the filament current calibration data corresponding to thefirst calibration point based on the updated first value of tube currentto be calibrated and the value of the filament current to be calibrated.

In some embodiments, generating the filament current calibration datacorresponding to the first calibration point based on the updated firstvalue of the tube current to be calibrated and the value of the filamentcurrent to be calibrated may further include, assigning an initial valueto an iteration number; updating the iteration number based on asituation of updating the first value of the tube current to becalibrated to the actual value of the tube current; comparing theiteration number with an iteration-number threshold, and reporting anerror if the iteration number is larger than the iteration-numberthreshold.

In some embodiments, the actual value of the tube current may correspondto at least one of a value of the tube current at an emission time pointduring the emission operation, or an average value of a plurality ofvalues of the tube current at a plurality of emission time points duringthe emission operation.

In some embodiments, the method may further include calibrating aplurality of calibration points, the plurality of calibration pointscorresponding to a value of tube voltage, the plurality of calibrationpoints including the first calibration point and a second calibrationpoint, the second calibration point corresponding to at least a secondvalue of the tube current to be calibrated, the first value of the tubecurrent to be calibrated being in a first interval, the second tubecurrent value to be calibrated being outside the first interval.

In some embodiments, the method may further include calibrating thefirst calibration point to determine fourth filament current calibrationdata; performing, based on the fourth filament current calibration data,data fitting; determining, based on a result of the data fitting, thesecond value of the tube current to be calibrated corresponding to thevalue of the tube voltage value; and determining, based on the secondvalue of the tube current to be calibrated, the second calibrationpoint.

In some embodiments, the method may further include determining firstfilament current calibration data corresponding to a first value of tubevoltage; determining second filament current calibration datacorresponding to a second value of the tube voltage; and determiningthird filament current calibration data corresponding to a third valueof the tube voltage based on a difference between the first value of thetube voltage and the second value of the tube voltage, and at least oneof the first filament current calibration data or the second filamentcurrent calibration data.

According to yet another aspect of the present disclosure, a method forpreheating a filament of an X-ray tube is provided. The method mayinclude determining a value of tube voltage, a value of tube current, astart time for emission, and a start time for preheating; determining,based on the start time for emission and the start time for preheating,a time length of preheating of the filament; establishing a heatingmodel; determining a filament preheating plan according to the value ofthe tube voltage, the value of the tube current, the time length ofpreheating of the filament, and the heating model; and performing, basedon the filament preheating plan, a filament preheating operation.

According to yet another aspect of the present disclosure, a system forpreheating a filament of an X-ray tube is provided. The system mayinclude a preheating module. The preheating module may be configured todetermine a value of tube voltage, a value of tube current, a start timefor emission, and a start time for preheating. The preheating module maybe configured to determine, based on the start time for emission and thestart time for preheating, a time length of preheating of the filament;establish a heating model; determine a filament preheating planaccording to the value of the tube voltage, the value of the tubecurrent, the time length of preheating of the filament and the heatingmodel; and perform, based on the filament preheating plan, afilament-preheating operation.

According to yet another aspect of the present disclosure, anon-transitory computer readable medium is provided, includingexecutable instructions that, when executed by at least one processor,cause the at least one processor to effectuate a method. The method maybe used for preheating a filament of an X-ray tube. The method mayinclude determining a value of tube voltage, a value of tube current, astart time for emission, and a start time for preheating; determining,based on the start time for emission and the start time for preheating,a time length of preheating of the filament; establishing a heatingmodel; determining a filament preheating plan according to the value ofthe tube voltage, the value of the tube current, the time length ofpreheating of the filament and the heating model; and performing, basedon the filament preheating plan, a filament-preheating operation.

In some embodiments, the method for preheating the filament of the X-raytube may further include determining, based on the heating model, timeinformation corresponding to a value of filament preheating currentcorresponding to the filament preheating plan, and the filamentpreheating plan may include the value of the filament preheating currentand the time information corresponding to the value of the filamentpreheating current.

In some embodiments, the heating model may include a time length of afirst standard preheating and a time length of a second standardpreheating, and determining, based on the heating model, the timeinformation corresponding to the value of the filament preheatingcurrent corresponding to the filament preheating plan may includecomparing the time length of preheating of the filament with the timelength of the first standard preheating and the time length of thesecond standard preheating; if the time length of preheating of thefilament is smaller than the time length of the first standardpreheating, determining the value of the filament preheating current asa first filament preheating current; if the time length of preheating ofthe filament is larger than or equal to the time length of the firststandard preheating and smaller than the time length of the secondstandard preheating, determining the value of the filament preheatingcurrent as a second filament preheating current; and if the time lengthof preheating of the filament is larger than or equal to the time lengthof the second standard preheating, determining the value of the filamentpreheating current as a third filament preheating current.

In some embodiments, performing, based on the filament preheating plan,the filament-preheating operation may include determining whether aninstruction of an X-ray loading plan is received, and performing, basedon the determination as to whether an instruction of an X-ray loadingplan is received, at least one operation.

In some embodiments, performing, based on the determination as towhether an instruction of an X-ray loading plan is received, the atleast one operation may include determining, based on a determination ofnot receiving the instruction of an X-ray loading plan, a time lengthbeyond the time length of preheating; and updating, based on the timelength beyond the time length of preheating, the filament preheatingplan.

In some embodiments, performing, based on the determination as towhether an instruction of an X-ray loading plan is received, the atleast one operation may include performing, based on a determination ofreceiving the instruction of an X-ray loading plan, the instruction ofthe X-ray loading plan.

In some embodiments, determining the filament preheating plan mayfurther include determining an initial value or an equivalentdescription value of a filament temperature, and determining, based onthe initial value or the equivalent description value of the filamenttemperature, the filament preheating plan.

In some embodiments, determining the initial value or the equivalentdescription value of the filament temperature may further includeobtaining a first emission plan and a second emission plan; determining,based on the first emission plan and the second emission plan, theinitial value or the equivalent description value of the filamenttemperature.

In some embodiments, determining, based on the initial value or theequivalent description value of the filament temperature, the filamentpreheating plan may further include determining an emission timeinterval between an end time for emission of the first emission plan anda start time for emission of the second emission plan; determining adifference between a value of the tube current of the first emissionplan and a value of the tube current of the second emission plan;determining a time length of preheating of a second emission based onthe difference and a heating model; comparing the emission time intervalwith the time length of preheating of the second emission; and reportingan error when the emission time interval is smaller than the time lengthof preheating of the second emission.

Additional features will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the artupon examination of the following and the accompanying drawings or maybe learned by production or operation of the examples. The features ofthe present disclosure may be realized and attained by practice or useof various aspects of the methodologies, instrumentalities andcombinations set forth in the detailed examples discussed below.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to illustrate the technical solutions related to theembodiments of the present disclosure, brief introduction of thedrawings referred to the description of the embodiments is providedbelow. Obviously, drawings described below are only some examples orembodiments of the present disclosure. Those having ordinary skills inthe art, without further creative efforts, may apply the presentdisclosure to other similar scenarios according to these drawings.Unless stated otherwise or obvious from the context, the same referencenumeral in the drawings refers to the same structure and operation.

FIG. 1 illustrates an application scene schematic diagram of anexemplary imaging system according to some embodiments of the presentdisclosure;

FIG. 2 illustrates a schematic diagram of an exemplary computeraccording to some embodiments of the present disclosure;

FIG. 3 illustrates a schematic diagram of an exemplary system for X-raytube filament current control according to some embodiments of thepresent disclosure;

FIG. 4 illustrates a module diagram of an exemplary imaging controldevice according to some embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of an exemplary process for X-ray tubefilament current control according to some embodiments of the presentdisclosure;

FIG. 6 illustrates a flowchart of an exemplary process for X-ray tubefilament calibration according to some embodiments of the presentdisclosure;

FIG. 7 illustrates a flowchart of an exemplary process for X-ray tubefilament calibration according to some embodiments of the presentdisclosure;

FIG. 8 illustrates a flowchart of an exemplary process for filamentcurrent calibration data generation corresponding to a calibration pointof according to some embodiments of the present disclosure;

FIG. 9 illustrates a flowchart of an exemplary process for X-ray tubepreheating plan generation according to some embodiments of the presentdisclosure;

FIG. 10 illustrates a flowchart of an exemplary process for X-ray tubepreheating plan generation according to some embodiments of the presentdisclosure;

FIG. 11 illustrates a flowchart of an exemplary process for filamentpreheating plan generation according to some embodiments of the presentdisclosure; and.

FIG. 12 illustrates a flowchart of an exemplary process for filamentpreheating plan generation according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION

In order to illustrate the technical solutions related to theembodiments of the present disclosure, brief introduction of thedrawings referred to the description of the embodiments is providedbelow. Obviously, drawings described below are only some examples orembodiments of the present disclosure. Those having ordinary skills inthe art, without further creative efforts, may apply the presentdisclosure to other similar scenarios according to these drawings.Unless stated otherwise or obvious from the context, the same referencenumeral in the drawings refers to the same structure or operation.

As used in the disclosure and the appended claims, the singular forms“a,” “an,” and “the” include plural referents unless the content clearlydictates otherwise. In general, the terms “comprises,” “comprising,”“includes,” and/or “including” when used in the disclosure, specify thepresence of stated steps and elements, but do not preclude the presenceor addition of one or more other steps or elements.

Some modules of the data processing system may be referred to in variousways according to some embodiments of the present disclosure. However,any number of different modules may be used and operated in a clientterminal and/or a server connected to the system via a network. Thesemodules are intended to be illustrative, and different modules may beused in different aspects of the system and method.

According to some embodiments of the present disclosure, flowcharts areused to illustrate the operations performed by the system. It is to beexpressly understood that the operations above or below may or may notbe implemented in order. Conversely, the operations may be performed ininverted order, or simultaneously. Besides, one or more other operationsmay be added to the flowcharts, or one or more operations may be omittedfrom the flowcharts.

This application relates to medical imaging, and more particularly,relates to a system and method for X-ray tube filament control of themedical imaging system. The method for X-ray tube filament control mayinclude calibrating filament current and generating a filamentpreheating plan.

The filament control system may calibrate the corresponding relationshipbetween the filament current and tube current for a point to becalibrated during the calibration of the filament current. The point tobe calibrated may be a data point consisting of a value of filamentcurrent and a value of tube current and corresponding to a certain sizeof a focal point and tube voltage. In the calibration process, for avalue of the tube current to be calibrated, the filament control systemmay perform an emission operation and obtain an actual value of the tubecurrent in the emission process. The filament control system may comparethe value of the tube current to be calibrated and the actual value ofthe tube current, and calculate the difference between these two values.The filament control system may calibrate the value of the tube currentto be calibrated based on the difference. For example, if the differenceis satisfied with a certain preset condition, the filament controlsystem may record the actual value of the tube current and the value ofthe filament current as a set of calibrated filament current calibrationdata. As another example, if the difference is not satisfied the presetcondition, the filament control system may update the value of the tubecurrent to be calibrated to the actual value of the tube current, andperform the above calibration process again until a certain number ofiterations are completed or the filament current calibration datasatisfied the above conditions are obtained.

The filament control system may obtain filament current calibration dataof a calibration point where the value of the tube current is within acertain range based on the above method for the same focal point and thesame value of the tube voltage. The filament control system may fit thefilament current calibration data and obtain fitting values of a set ofcalibration points where the value of the tube current is outside theabove range. Based on these fitting values, the filament control systemmay perform the calibration of the method above to generate new filamentcurrent calibration data. In some embodiments, if these fitting valuesare too large or too small endpoint data, the filament control systemmay directly apply the fitting values as filament current calibrationdata in order to avoid filament overcurrent and the like. Based on theabove method, the filament control system may obtain a set of filamentcurrent calibration data corresponding to the value of the tube voltage.

For different values of the tube voltage, the filament control systemmay generate different filament current calibration data based on theabove method. For example, the filament control system may generate thefirst filament current calibration data corresponding to a first valueof the tube voltage and may generate the second filament currentcalibration data corresponding to a second value of the tube voltage.The filament control system may generate third filament currentcalibration data corresponding to a third value of the tube voltageusing the interpolation algorithm based on the first filament currentcalibration data and the second filament current calibration data.

The filament preheating plan may include one or more filament preheatingcurrents and time information (e.g., one or more time points, timeperiods) corresponding to the one or more filament preheating currents.A method of the filament control system may be applied to differentscenes during the generation of the filament current preheating plan. Inone scene, the filament control system may determine a filament preheatplan based on the emission start time in an emission plan and a value ofan emission tube current. In one scene, the time interval between theprevious emission and the next emission is relatively short, and theX-ray tube filament is not completely cooled. The filament controlsystem may generate a filament preheating plan based on the previousemission plan and the current emission plan. In one scene, an imagingsystem fails to receive an X-ray emission instruction after thepreheating plan is performed. The filament control system may update thepreheating plan based on the X-ray emission instruction to preventoverheating.

FIG. 1 illustrates an application scene schematic diagram of anexemplary imaging system 100 according to some embodiments of thepresent disclosure. The imaging system 100 may include an imaging device110, an imaging control device 120, a terminal 130, a display 140, adatabase 150, and a network 160. In some embodiments, at least a portionof the imaging control device 120 may be implemented by a computer 200as shown in FIG. 2 .

Different components/assemblies in the imaging system 100 maycommunicate with each other. For example, the imaging control device 120may be interconnected or communicated with the network 160 or may bedirectly interconnected or communicated with the imaging system 100 or aportion thereof (e.g., the imaging device 110, the terminal 130), or acombination of both. For example, the imaging control device 120 maytransmit data to the terminal 130, obtain one or more user instructionsfrom the terminal 130, send one or more control instructions and thelike to the imaging device 110, and exchange data with the database 150,etc. The data communication among the imaging device 110, the imagingcontrol device 120, the terminal 130, the display 140, the database 150,and other devices which may be included in the imaging system 100 may beimplemented by a data cable, the network 160, or the like, or acombination thereof.

The imaging device 110 may be used to obtain imaging data. For example,the imaging device 110 may scan a target object and obtain data (e.g.,scanning data) associated with the target object. The imaging device 110may be a single device or a group of devices. In some embodiments, theimaging device 110 may be a medical information collection device, suchas a positron emission tomography (PET) device, a single-photon emissioncomputed tomography (SPECT) device, a computed tomography (CT) device,and a magnetic resonance imaging (MRI) device, etc. The device may beused independently or in combination. The imaging device 110 may be aPET-CT device, a PET-MRI device, or a SPECT-MRI device, etc. Thescanning data may be data related to the signal data obtained by theimaging device 110 after signal data (e.g., an X-ray signal, a magneticfield signal) emitted from the imaging device 110 passes through anobject (e.g., a human body). The scanning data may be CT scanning data,MRI scanning data, ultrasonic scanning data, X-ray scanning data, or thelike, or any combination thereof.

The imaging device 110 may generate an image based on the obtained data.For example, the imaging device 110 may generate an image based on thescanning data. The scanning data may be from the imaging device 110 orthe database 150. The generated image contains information of thescanned object. The operation of scanning data to generate the image mayinclude data superposition, Fourier transformation, conversion of signalstrength into gray value, three-dimensional reconstruction,multimodality fusion, or the like, or any combination thereof. Thegenerated image may be a two-dimensional image (e.g., a section image),a three-dimensional reconstruction image, a four-dimensionalreconstruction image, a multimodality image, or the like, or anycombination thereof. The generated image may be a grayscale image, ablack-and-white image, a binary image, or a color image, etc. In theprocess of generating the image based on the scanning data, the imagingcontrol device 120 may further use one or more data processingoperations, such as a data preprocessing, data conversion processing,data cleaning processing, data fitting processing, data weightingprocessing, or the like, or any combination thereof.

The imaging device 110 may include a scanning component. The scanningcomponent may scan the target object. The scanning component may be aradioactive scanning device. The radioactive scanning device may includea radioactive source. The radioactive source may emit radioactive rays.The radioactive rays may include a particle ray, a photon ray, or thelike, or any combination thereof. The particle ray may include neutrons,protons, a-rays, electrons, p mediums, heavy ions, or the like, or anycombination thereof. The photon ray may include X-rays, y-rays,ultraviolet rays, lasers, or the like, or any combination thereof. Forexample, the photon ray may be X-rays. Accordingly, the imaging device110 may be a CT system, a digital radiography (DR) system, amultimodality medical imaging system, or the like, or any combinationthereof. The multi-modality medical imaging system may include a CT-PETsystem, an SPECT-MRI system, or the like, or any combination thereof.The imaging device 110 may also include a ray detection unit (not shownin FIG. 1 ) to complete the detection of the generated rays, etc.

The imaging control device 120 may perform imaging control. The imagingcontrol may be control of one or more components or devices of theimaging system 100 (e.g., the scan component in the imaging device 110,the display 140, and the terminal 130). For example, the imaging controldevice 120 may generate a filament preheating plan, and the imagingdevice 110 may perform a filament preheating operation based on thefilament preheating plan. The imaging control device 120 may control theimaging device 110 by control instructions. The control instructions maybe generated based on data generated by the imaging control device 120or may be generated based on data (e.g., user instructions) obtainedfrom other devices (e.g., the terminal 130). In some embodiments, theimaging control device 120 may generate a control instruction based onone or more user instructions. For example, the control instruction maybe an adjustment of one or more parameters of the imaging device 110.The parameters may include a filament preheating time, filamentpreheating current, tube voltage, tube current, or the like, or anycombination thereof. The imaging device 110 may perform operations suchas filament preheating based on the control instructions.

In some embodiments, the imaging control device 120 may transmit data tothe database 150 or read data from the database 150. The data may bedata directly or indirectly obtained from the imaging device 110,temporary or non-temporary data generated by the imaging control device120, or data for assisting the imaging control device 120 to performimaging control, etc.

In some embodiments, the imaging control device 120 may be a singlecomputer or a group of computers. The group of computers forimplementing the imaging control device 120 may be in wired connectionor wireless connection (e.g., via the network 160). The group ofcomputers for implementing the imaging control device 120 may indirectlycommunicate with each other via one or more devices. The imaging controldevice 120 may be installed in a same geographic location as the imagingdevice 110. The imaging control device 120 may be architected in thecloud. In some embodiments, the imaging control device 120 may be acomponent of the imaging device 110. The terminal 130 may be a componentof the imaging device 110 or an independent device.

The terminal 130 may be connected or communicated with the imagingcontrol device 120. The terminal 130 may allow one or more users (e.g.,a doctor, an image technician) to control the generation or display ofan image (e.g., displayed on the display 140). The terminal 130 mayinclude an input device, an output device, a control panel (not shown inFIG. 1 ), or the like, or any combination thereof. The input device mayinclude a keyboard, a touch control device, a mouse, keys, an audioinput device (e.g., a microphone), an image input device (e.g., ascanner, a camera), a remote control device (e.g., a remote control, aremotely connected computer), a data input device (e.g., an opticaldrive, a USB port), or the like, or any combination thereof. A user mayinput user operation data via the input device. The manner in which theuser inputs data may include but not limited to a mouse operation,keyboard input, a key operation, a touch control operation, a voicecontrol operation, an expression operation, a somatosensory operation, aneural signal operation, or the like, or any combination thereof. Insome embodiments, the user may input information such as instrumentparameters, data processing parameters, image display parameters, or thelike directly or indirectly to the terminal 130, the imaging controldevice 120, the imaging device 110 and/or other devices/components whichmay exist in the imaging system 100 via the input device. The inputinformation may be from external data sources (e.g., a floppy disk, ahard disk, an optical disk, a memory chip, the network 160, or the like,or any combination thereof).

The display 140 may display information. The information may includeerror information in a filament calibration and a filament preheatingprocess, a filament preheating plan, an emission plan, data used and/orgenerated in the filament calibration or the filament preheatingprocess, or the like, or any combination thereof. The display 140 mayinclude a liquid crystal display (LCD), a light emitting diode(LED)-based display, a flat panel display or a curved surface display(or a television), a cathode ray tube (CRT), or the like, or anycombination thereof.

The database 150 may be used to store data. The stored data may be datagenerated or obtained by the imaging system 100, such as scanning data,data generated when one or more components of the imaging system 100operate, data input by the user via the terminal 130, data obtained bythe user from other data sources (not shown in FIG. 1 ) via the network160, etc. The stored data may include data of the X-ray tube (e.g., tubecurrent, filament current). The database 150 may be a device/componentor a combination of multiple devices/components having a memoryfunction. In some embodiments, the database 150 may include one or moreindependent devices having a data memory function, for example, acomputer, a server, etc. The database 150 may include a local memory ora remote memory (e.g., a cloud platform connected to the network 160).In some embodiments, the database 150 may include a component having adata memory function in an independent device, for example, a disk, or adisk array, etc. The database 150 may include components having a memoryfunction of any device in the imaging system 100 (e.g., the imagingdevice 110, the imaging control device 120, the terminal 130).

In some embodiments, the database 150 may store scanning data. Thescanning data may be from the imaging device 110, the terminal 130(e.g., obtained via a mobile memory device socket), the network 160,etc. For example, the database 150 may store CT scanning data and/or MRIscanning data. In some embodiments, the database 150 may store temporarydata/images or non-temporary data/images generated when the imagingcontrol device 120 and/or the terminal 130 are in normal operation. Forexample, the database 150 may store some system operation temporaryfiles, scanning images, output images, temporary data/images, etc. Insome embodiments, the database 150 may store information collected bythe terminal 130 from the user or data generated based on theinformation, for example, user operation data, user input data, userinstructions, authentication data, etc.

In some embodiments, the database 150 may store program codes (e.g.,software, an operation system) for running the imaging device 110, theimaging control device 120 and/or the terminal 130, etc. The database150 may also store data of one or more algorithms/models, parameterdata, reference data/images, etc. The program code, algorithm/modeldata, parameter data, standard data and the like may be added to thedatabase 150 by an installer when a program for implementing one or morefunctions of the imaging system 100 is installed, or added to thedatabase 150 by the user via the terminal 130 or the network 160.

The network 160 may be used to transfer information among variousdevices/components in the imaging system 100. The network 160 may be anindependent network or a combination of various networks. For example,the network 160 may include a local area network (LAN), a wide areanetwork (WAN), a public switched telephone network (PSTN), a virtualnetwork (VN), or the like, or any combination thereof. The network 160may include a plurality of network access points. The network 160 mayuse a wired network architecture, a wireless network architecture, and awired/wireless network hybrid architecture. A wired network may includea metal cable, a hybrid cable, an optical cable, or the like, or anycombination thereof. The transmission method of the wireless network mayinclude Bluetooth™, Wi-Fi, ZigBee™, Near Field Communication (NFC),cellular networks (including GSM, CDMA, 3G, 4G), or the like.

It should be noted that the above description of the imaging system 100is provided merely for illustration, and is not intended to limit thescope of the present disclosure. It may be appreciated that for personshaving ordinary skills in the art, after understanding the principle ofthe system, various changes in details can be made on the imaging system100, such as any combination of a plurality ofdevices/assemblies/modules (e.g., the imaging control device 120, thedatabase 150, and the terminal 130 are combined into one device), asplit of a single device/assembly/module (e.g., the imaging controldevice 120 is split into one or more devices for performing one or morefunctions of the imaging control device 120 respectively), addingdevices/assemblies not related to the present invention (e.g., afiltering device) for the imaging system 100, changing the connectionbetween the main devices/assemblies from a direct connection to anindirect connection (e.g., adding one or more signal receiving andtransmitting devices and transcoding devices), changing the type of theimaging device 110 so as to apply the system to different fields, etc.,however, these changes may not depart from the scope of the claims.

FIG. 2 illustrates a schematic diagram of an exemplary computer 200according to some embodiments of the present disclosure. The computer200 may be applied to the imaging system 100, any devices/componentsincluded in the imaging system 100 (e.g., the imaging control device120, the terminal 130), functional modules included in thedevices/components (e.g., a calibration module 410, a preheating module420), functional units included in the functional modules (e.g., a tubecurrent determination unit 412, a preheating time determination unit423) and the like to implement one or more functions of the system,device, component, module, unit or the like in the present disclosure.The computer 200 may implement one or more functions (e.g., filamentcalibration, generation of a filament preheating plan) of the imagingsystem 100 via its hardware device, software program, firmware andcombinations thereof. The computer 200 may have a general applicationscene or a special application scene (e.g., application of generating,processing, displaying medical images). The computer 200 may be a singlecomputer or a group of computers. For convenience, only one computer 200is shown in FIG. 2 , but a function of the imaging system 100 describedherein (e.g., scanning data acquisition, data processing, imageprocessing) may be implemented in a distributed manner on some similarcomputer platforms (parallel or serial) to distribute the processingload.

The computer 200 may include an internal communication bus 210, acentral processing unit (CPU) 220, a data memory unit (e.g., a read-onlymemory (ROM) 230, a random access memory (RAM) 240, a hard disk 250), anI/O component 260, communication (COM) ports 270, etc. The internalcommunication bus 210 may be used to transfer data between differentcomponents of the computer 200. The CPU 220 may be used to execute oneor more instructions (including user instructions, program instructions,control instructions) and to assume one or more algorithms (e.g., aninterpolation algorithm). The CPU 220 may include a single chip or agroup of chips. One or more functions of the imaging control device 120may be implemented by the CPU 220. The computer 200 may further includea graphics processing unit (GPU) (not shown in FIG. 2 ) for assistingthe CPU 220 in processing graphics data. The graphics processing unitmay be an independent component in the computer 200 or may beencapsulated on a same chip as the central processing unit.

The read-only memory 230, the random access memory 240 and the hard disk250 may store various data files or programs involved in processes suchas computer operations, computer communications, computer functionimplementation, etc. (more detailed description may refer to the relateddescription of database 150 in FIG. 1 ). The I/O component 260 maysupport the computer 200 to perform data communication with one or moreperipheral devices 280. The I/O component 260 may include one or moreconnection ports, such as COM ports (communication ports), USB(Universal Serial Bus) ports, HDMI (High-Definition MultimediaInterface) ports, VGA (Video Graphics Array) ports, DVI (Digital VideoInteractive) ports, PS/2 interfaces, etc. The peripheral device 280 mayperform data communication via the input/output component 260 and theinternal communication bus 210. The peripheral device 280 may be adevice for input or output, for example, a display, a printer, a mouse,a keyboard, a handle, a touch screen, a camera, a speaker, or the like,or any combination thereof. The peripheral device 280 may include one ormore input components and output components in the terminal 130 (moredetailed description may refer to the related description of theterminal 130 in FIG. 1 ). The COM ports 270 may perform datacommunication via one or more networks (more detailed description mayrefer to the related description of the network 160 in FIG. 1 ).

FIG. 3 illustrates a schematic diagram of an exemplary system 300 forX-ray tube filament current control according to some embodiments of thepresent disclosure. The system 300 may include an imaging control device120, a high voltage generator 320, and an X-ray tube 330.

The imaging control device 120 may communicate with the high voltagegenerator 320. For example, the imaging control device 120 may controlthe amplitude of the voltage generated by the high voltage generator320. In some embodiments, the imaging control device 120 may send aninstruction to the high voltage generator 320, and the instruction mayinclude a filament preheating instruction, an instruction of an X-rayloading plan, etc. The instruction of the X-ray loading plan may be aninstruction to perform an X-ray loading operation. The instruction ofthe X-ray loading plan may be an instruction including parametersrequired for X-ray loading (e.g., X-ray loading time, X-ray radiationintensity). Relevant parameters (e.g., X-ray loading time, X-rayradiation intensity) of the X-ray loading may be determined based on theinstruction of the X-ray loading plan. The high voltage generator 320may receive the instruction and perform one or more operations. Theoperations may include adjusting the amplitude of the voltage generatedby the high voltage generator 320, etc. The high voltage generator 320may feed information back to the imaging control device 120. Theinformation may include information, for example, the voltage amplitudeof the high voltage generator 320, etc. The imaging control device 120may include a console 121, and a gantry processor 122.

One or more components (e.g., a master processor 1212, a heating model1213) in the console 121 may send information (e.g., filament currentinformation, preheating time information) to the gantry processor 122.The gantry processor 122 may generate an instruction (e.g., a filamentpreheating instruction) based on the information and send theinstruction to the high voltage generator 320. The console 121 mayinclude a user interface 1211, a master processor 1212, and a heatingmodel 1213.

The user interface 1211 may receive setting for a parameter of theimaging system 100 by the user. The parameter may be an emission planparameter, such as tube voltage, tube current, a start time foremission, etc. For example, the user may set the start time for emissionduring an emission operation of the imaging system 100 via the userinterface 1211.

The master processor 1212 may be used for processing of information. Theinformation may be an emission plan parameter (e.g., tube voltage, tubecurrent, a start time for emission), a heating model, etc. Theprocessing operation may include generating a filament preheating plan,determining a filament preheating time, calibrating the correspondingrelationship between the tube current of the filament and the filamentcurrent, performing a mathematical operation (e.g., an iterativeoperation, an interpolation operation), etc.

The master processor 1212 may obtain information from the user interface1211, the heating model 1213, the database 150, etc. The masterprocessor 1212 may send the processed information to the gantryprocessor 122 or may save the processed information into the database150 or other memory devices. The manner of information processing mayinclude storage, classification, calculation, conversion of theinformation, or the like, or any combination thereof.

In some embodiments, the master processor 1212 may obtain an emissionplan from the user interface 1211. The master processor 1212 maygenerate a filament preheating plan based on the emission plan. Thefilament preheating plan may include information such as one or morefilament preheating currents, and time information corresponding to theone or more filament preheating currents. For example, the filamentpreheat plan may include preheating with certain filament preheatingcurrent (e.g., current of 3.5 A) within a period (e.g., within a periodof from 1.0 s to 1.5 s). The filament preheating current may be filamentcurrent corresponding to the filament preheating process. The filamentcurrent may be determined by the voltage of the filament provided by thehigh voltage generator 320. The master processor 1212 may send thefilament preheating plan to the gantry processor 122. The gantryprocessor 122 may generate a filament preheating instruction based onthe filament preheating plan. The high voltage generator 320 may performa preheating operation based on the filament preheating instruction.

In some embodiments, the master processor 1212 may perform a calibratingoperation of the filament current. The calibrating operation may includecalibration of a first calibration point and a second calibration point.The first calibration point may be one or more preset calibration points(e.g., data of tube current and filament current provided by themanufacturer when the X-ray tube left a factory). The second calibrationpoint may be one or more fitting values. Techniques used in thecalibration may include an iterative operation technique, a curvefitting technique, an interpolation operation technique, etc.

The heating model 1213 may be used to establish a heating model. Theheating model 1213 may be stored in advance in the memory inside oraround the master processor 1212. The master processor 1212 may obtainone or more heating models from the heating model 1213. The heatingmodels may include a corresponding relationship of tube voltage, tubecurrent, a time length of preheating of a filament, and filamentpreheating current. The heating models may exist in the form of a datatable and may exist in the form of a function.

In some embodiments, establishing a model may include determining amodel (e.g., performing one or more steps described in 940 of FIG. 9 ,or performing one or more steps described in 1140 of FIG. 11 ). In someembodiments, establishing a model may include selecting a heating modelfrom one or more heating models (e.g., selecting one from Table 1 orTable 2 as a heating model). In some embodiments, establishing a modelmay include reading the model from memory or obtaining the model inother ways.

The high voltage generator 320 may generate a high voltage and provideit to the X-ray tube 330. The high voltage may be applied between acathode and an anode of the X-ray tube 330. Merely by way of example,the high voltage may be a voltage within a voltage range (e.g., a rangefrom 30 kV to 150 kV). The high voltage generator 320 may also provide avoltage to a cathode filament of the X-ray tube 330. The cathodefilament of the X-ray tube 330 may produce filament current under thevoltage. Merely by way of example, the filament current may be a valuewithin a current range (e.g., within a range from 3 A to 3.5 A), and thefilament current may be a constant value (e.g., 3 A, 4 A, or 6.5 A).

The X-ray tube 330 may generate an X-ray beam. The X-ray tube 330 may bea cold cathode tube, a high vacuum hot cathode tube, a rotating anodetube, etc. The shape of the X-ray beam may include a line shape, apencil shape, a sector shape, a cone shape, a wedge shape, an irregularshape, or the like, or any combination thereof. The X-ray tube 330 mayinclude a cathode, an anode and a housing (not shown in FIG. 3 ). Thecathode may emit electrons. The anode may accept electron bombardmentand produce an X-ray beam. The anode and the cathode may be sealed inthe housing. The housing may provide a vacuum environment to ensure thatthe electron movement is not blocked. The housing may consist ofheat-resistant glass or a metal frame. The cathode may include afilament. The filament may be composed of a high melting point metalmaterial (e.g., tungsten). When the filament current flows through thefilament, the filament may be heated to release electrons. The electronsmay be capable of impacting the anode at high speed under the action ofa high voltage between the cathode and the anode. After the electronsreach the anode, the movement may be blocked and energy conversionoccurs, and a part of kinetic energy of the electron may be convertedinto radiant energy. The radiant energy may be released in the form ofan X-ray beam. The high voltage electric field between the cathode andthe anode may be referred to as tube voltage. The current formed by thehigh-speed movement of the electrons between the cathode and the anodemay be referred to as tube current. The region which absorbs electronsand produces X-ray on the anode target surface may be referred to as afocal point.

FIG. 4 illustrates a module diagram of an exemplary imaging controldevice 120 according to some embodiments of the present disclosure. Theimaging control device 120 may include a calibration module 410, apreheating module 420, an I/O module 430, and a storage module 440.

The calibration module 410 may perform a filament calibration operation.The filament calibration operation may include calibrating acorresponding relationship between tube current and filament current.The calibration operation may include determining filament currentcalibration data. The calibration operation may also include datafitting based on the filament current calibration data. The calibrationoperation may generate third filament current calibration datacorresponding to the third value of tube voltage based on first filamentcurrent calibration data corresponding to a first value of the tubevoltage and second filament current calibration data corresponding to asecond value of the tube voltage. Techniques used in the filamentcalibration operation may include an iterative operation technique, acurve fitting technique, an interpolation operation technique, etc. Thecurve fitting technique may include a least square method, etc. Theinterpolation operation technique may include a Lagrange interpolationalgorithm, a Newton interpolation algorithm, a Hermite interpolationalgorithm, etc.

The calibration module 410 may include a data fitting unit 411, a tubecurrent determination unit 412, and a calibration data storage unit 413.

The data fitting unit 411 may perform a data fitting operation. The datafitting operation may be completed based on any data associated with theimaging system 100. For example, the data may include tube current,filament current, a focal point size, tube voltage, etc. The datafitting operation may include determining the corresponding relationshipbetween the tube current and the filament current at a specific focalpoint size and a value of the tube voltage. The data fitting unit 411may fit the data using one or more data fitting techniques. The datafitting techniques may include a linear fitting technique, a curvefitting technique, etc. For example, the data fitting technique may be aleast square method, etc.

The data fitting unit 411 may determine one or more second calibrationpoints based on a fitting result. The second calibration point may be acalibration point for the value of the tube current within a currentvalue interval (e.g., a current value interval outside a first tubecurrent value interval). For example, Table 1 shows a case of focalpoint size 1 and tube voltage of 70 kV, the second calibration point maybe a calibration point corresponding to the value of the tube currentoutside an interval from 30 mA to 300 mA. For example, calibrationpoints corresponding to values of the tube current of 10 mA, 400 mA, 500mA, and 600 mA.

The tube current determination unit 412 may determine an actual value ofthe tube current. The actual value of the tube current may be a value ofthe tube current corresponding to a specific time (e.g., a time point, atime period), or may be a value (e.g., an average value of values of thetube current at a plurality of times) calculated based on values of thetube current of a plurality of times (e.g., a plurality of time points,a plurality of time periods). The actual value of the tube current maybe an actual value of the tube current in an emission process or actualvalues of the tube current in a plurality of emission processes. Forexample, in an emission process, a value of the tube current at T1 timeis a first value (e.g., mA1), a value of the tube current at T2 time isa second value (e.g., mA2), and a value of the tube current at T3 timeis a third value (e.g., mA3). In some embodiments, the actual value ofthe tube current may be the first value (mA1), the second value (mA2),and/or the third value (mA3). In some embodiments, the actual value ofthe tube current may also be an average value of the first value (mA1),the second value (mA2), and the third value (mA3).

The calibration data storage unit 413 may store one or more calibrationdata. The calibration data may include calibration point data andfilament current calibration data. The calibration point data mayinclude a set of one or more calibration points. The calibration pointmay include a focal point size, a value of tube voltage, a value of tubecurrent, filament current, etc. The calibration point may be a defaultpoint or a fitting point. The default point may be a calibration pointcorresponding to a value of the tube current within a default range(e.g., 30 mA to 300 mA shown in Table 1). Data of the default point maybe preset data (e.g., data provided by the manufacturer when the X-raytube leaves factory). The interpolation point may be a calibration pointcorresponding to a value range of the tube current outside the defaultrange. The interpolation point may also include a maximum endpoint and aminimum endpoint (e.g., a fitting point in Table 1). The interpolationpoint may be a calibration point obtained based on the data fittingresult. The filament current calibration data may correspond to acalibration point, including a tube current datum and a filament currentdatum.

In some embodiments, the calibration point data may include one or moredata as shown in Table 1. The calibration point data in Table 1 maycorrespond to a specific value of the filament current (e.g., 10 mA).The calibration point data in Table 1 may include a focal point size, avalue of tube voltage, and a value of tube current. In some embodiments,a focal point size may correspond to a plurality of tube voltage data.For example, focal point size 1 may correspond to a plurality of valuesof the tube voltage, which are 10 kV, 80 kV, 100 kV, 120 kV, and 140 kVrespectively. In some embodiments, tube voltage may correspond to aplurality of tube current data. For example, as shown in Table 1, valueof the tube voltage of 70 kV may correspond to a plurality of values ofthe tube current, which are 6 mA, 10 mA, 30 mA, 60 mA, 120 mA, 200 mA,300 mA, 400 mA, 500 mA, 600 mA, and 610 mA respectively.

TABLE 1 Calibration Point Data corresponding to Specific FilamentCurrents, different Focal Point Sizes and different Values of the TubeVoltage. Focal Point Size 1 Focal Point Size 2 Tube Voltage (kV) 70 80100 120 140 70 80 100 120 140 Tube Current (mA) kV kV kV kV kV kV kV kVkV kV Endpoint (Fitting Point) 6 6 6 6 6 6 6 6 6 6 Interpolation Point10 10 10 10 10 10 10 10 10 10 (Fitting Point) Default Point 30 30 30 3030 30 30 30 30 30 60 60 60 60 60 60 60 60 60 60 120 120 120 120 120 100100 100 100 100 200 200 200 200 200 140 150 150 150 150 300 300 300 300300 180 200 220 220 220 Interpolation Point 400 400 450 400 400 220 250280 300 310 (Fitting Point) 500 530 600 550 600 600 670 770 700 Endpoint(Fitting Point) 610 680 780 833 714 230 260 290 310 320

The preheating module 420 may generate a filament preheating plan. Thefilament preheating plan may include information such as one or morefilament preheating current values and time information corresponding tothe one or more filament preheating current values. The operation ofgenerating the filament preheating plan may include determining afilament temperature, determining a preheating time length, building aheating model, etc. The preheating module 420 may include a filamenttemperature determination unit 421, a preheating time determination unit423, and a preheating plan generating unit 425.

The filament temperature determination unit 421 may determine a filamenttemperature. Determination of the filament temperature may bedetermining an initial value of the filament temperature. Determinationof the filament temperature may be determining an equivalent descriptionvalue of the filament temperature. The equivalent description value ofthe filament temperature may describe the thermionic emission capabilityof a filament, such as thermionic energy, energy level, the surfacebarrier of the filament, etc. In some embodiments, the filamenttemperature determination unit 421 may determine the filamenttemperature based on a value of tube voltage of a first emission, avalue of tube current of the first emission, an end time for the firstemission, a start time for a second emission, and/or a heating model(e.g., a filament heat dissipation table). The heating model may includethe corresponding relationship between the filament temperature and anemission time interval at a value of the tube voltage and a value of thetube current of the first emission. For example, the heating model mayexist in the form of a filament heat dissipation table shown in Table 5(see details of the description of FIG. 11 ). As another example, theheating model may exist in the form of a function. The emission timeinterval may include a time interval between an end time for the firstemission and a start time for the second emission. In some embodiments,the filament temperature determination unit 421 may directly obtain thefilament temperature from the imaging device 110. For example, theimaging system 100 may include a thermometer for measuring the filamenttemperature. The filament temperature determination unit 421 may obtainthe filament temperature from the thermometer.

The preheating time determination unit 423 may determine preheating timeinformation. The preheating time information may include a start timefor preheating, an end time for preheating, a start time for emission,an end time for emission end time, a time length of preheating of afilament, etc. The time length of preheating of the filament may be atime difference from the start time for preheating to the start time foremission. The preheating time determination unit 423 may determine thestart time for emission based on an emission plan.

The preheating plan generation unit 425 may generate a filamentpreheating plan. In some embodiments, the preheating plan generationunit 425 may generate the filament preheating plan based on a value oftube voltage, a value of tube current, a time length of preheating of afilament, and a heating model. In some embodiments, the preheating plangeneration unit 425 may generate the filament preheating plan based on avalue of tube voltage, a value of tube current, a time length ofpreheating of a filament, a filament temperature, and a heating model.In some embodiments, the preheating plan generation unit 425 maygenerate the filament preheating plan based on a difference between avalue of tube current of a first emission and a value of tube current ofa second emission, and a heating model. In some embodiments, thepreheating plan generation unit 425 may determine whether to modify thefilament preheating plan based on whether an instruction of an X-rayloading plan is received.

The I/O module 430 may receive information from one or more othermodules or components of the imaging system 100 (e.g., the calibrationmodule 410, the preheating module 420, the storage module 440, and thedatabase 150), and send the information to one or more other modules orcomponents of the imaging system 100. The form of the information mayinclude text, audio, a video, a picture, or the like, or any combinationthereof. In some embodiments, the I/O module 430 may include a keyboard,a mouse, a display, or the like, or any combination thereof.

The storage module 440 may store data. The stored data may be datagenerated or obtained by the imaging control device 120, for example,filament preheating current data, data produced by one or more modulesof the imaging control device 120 when operating, data from the database150 input through the I/O module 430, etc. In some embodiments, thestorage module 440 may be incorporated into the calibration module 410and/or the preheating module 420, or the database 150 of FIG. 1 .

It should be noted that the above description of the imaging controldevice 120 is provided merely for the purpose of illustration, and isnot intended to limit the scope of the present disclosure. It may beappreciated that for persons having ordinary skills in the art, afterunderstanding the principle of the system, various modifications andchanges in forms and/or various details can be made on the imagingcontrol device 120, however, these modifications and changes may notdepart from the scope disclosed by the present disclosure. For example,the imaging control device 120 may include some other components, forexample a communication interface, a power supply, etc. For example, thestorage module 440 may be omitted from the imaging control device 120and/or incorporated into the database 150 of FIG. 1 . For example, thecalibration data storage unit 413 may be incorporated into the storagemodule 440.

FIG. 5 illustrates a flowchart of an exemplary process 500 for X-raytube filament current control according to some embodiments of thepresent disclosure. In some embodiments, one or more operations inprocess 500 may be implemented by the imaging control device 120.

In 510, the process 500 may perform a calibration operation based oncalibration point data. The calibration operation may be implemented bythe calibration module 410. The calibrating operation may be generatingfilament current calibration data based on the calibration point data.The calibration point data may include data regarding one or morecalibration points. The calibration point data may include a focal pointsize, a value of tube voltage, a value of filament current, a value oftube current, etc. In some embodiments, the calibration point data maybe as shown in Table 1 (more details about Table 1 may be described withreference to FIG. 4 ). The techniques used in the calibrating operationmay include an iterative operation technique, a curve fitting technique,an interpolation operation technique, etc.

In 520, the process 500 may generate a first filament preheating planbased on a first emission plan. The operation of generating the firstfilament preheating plan may be implemented by the preheating module420. The first emission plan may include a value of tube voltage of afirst emission, a value of tube current of the first emission, a starttime for emission of the first emission, an end time for emission of thefirst emission, etc. The first emission plan may be obtained from theI/O module 430, the storage module 440, etc. The first filamentpreheating plan may include information such as one or more filamentpreheating current values, and time information corresponding to the oneor more filament preheating current values.

In 530, the process 500 may update the first filament preheating planbased on an instruction of an X-ray loading plan. The operation ofupdating the first filament preheating plan may be implemented by thepreheating module 420. The updating operation may include modifying oneor more parameters in the first filament preheating plan, for example,extending a preheating time. The update may include determining anincreased preheating time and determining a corresponding preheatingcurrent after the first filament preheating plan ends. In someembodiments, updating the first filament preheating plan may includeperforming one or more operations involved in the related description ofFIG. 10 .

In some embodiments, the imaging control device 120 may determinewhether the instruction of the X-ray loading plan is received. If theinstruction of the X-ray loading plan is received, the imaging system100 may execute the instruction of the X-ray loading plan. If theinstruction of the X-ray loading plan is not received, the imagingsystem 100 may modify the first filament preheating plan.

In 540, the process 500 may obtain a second emission plan. The secondemission plan may include a value of tube voltage of a second emission,a value of the tube current of the second emission, a start time foremission of the second emission, an end time for emission end time ofthe second emission, etc.

In 550, the process 500 may generate a second filament preheating planbased on the first emission plan and the second emission plan. Theoperation of generating the second filament preheating plan may beimplemented by the preheating module 420. The second filament preheatingplan may include information such as one or more filament preheatingcurrents, and time information corresponding to the one or more filamentpreheating current. In some embodiments, a filament temperature may bedetermined based on the first emission plan and the second filamentpreheating plan. The second filament preheating plan may be generatedbased on the filament temperature and the second emission plan. Forexample, generating the second filament preheating plan may includeperforming one or more operations involved in the related description ofFIG. 11 . In some embodiments, the second filament preheating plan maybe generated based on a difference between the value of the tube currentof the second emission and the value of the tube current of the firstemission. For example, generating the second filament preheating planmay include performing one or more operations involved in the relateddescription of FIG. 12 .

In 560, the process 500 may update the second filament preheating planbased on the instruction of the X-ray loading plan. The operation ofupdating the second filament preheating plan may be implemented by thepreheating module 420. The update of the second filament preheating planmay adopt the method described in step 530.

In some embodiments, a determination whether the instruction of theX-ray loading plan is received may be performed in step 530 and/or step560. If the instruction of the X-ray loading plan is received, theimaging system 100 may perform an emission operation. During theemission operation, in order to maintain the value of the tube currentin the vicinity of a target value of tube current in the emissionprocess, an actual value of the tube current may be monitored in theemission process. The difference between the actual value of the tubecurrent and the target value of the tube current may be obtained in themonitoring. Filament current in the emission process may be adjusted bya filament current control circuit based on the difference. By adjustingthe filament current, the difference may be controlled in a thresholdrange, so as to maintain the value of the tube current in the emissionprocess in the vicinity of the target value of the tube current.

It should be noted that the above description of the process 500 isprovided merely for illustration, and is not intended to limit the scopeof the present disclosure. It may be appreciated that for persons havingordinary skills, after understanding the principle of the system,various modifications and changes in forms and details may be made onthe specific ways and steps of the process 500, however, thosemodifications and changes may not depart from the scope of the claims ofthe present disclosure. In some embodiments, several steps in process500 may be omitted, for example, step 510 and step 530 may be omitted.

FIG. 6 illustrates a flowchart of an exemplary process 600 for X-raytube filament calibration according to some embodiments of the presentdisclosure. One or more operations in the process 600 may be implementedby the imaging control device 120.

In 602, the process 600 may determine the first filament currentcalibration data corresponding to the first value of tube voltage. Theoperation of determining the first filament current calibration data maybe implemented by the calibration module 410. The first filament currentcalibration data may include filament current calibration datacorresponding to one or more calibration points. The calibration pointsmay be default points or interpolation points. The first filamentcurrent calibration data may include a first value of the tube voltage,a value of tube current, a value of filament current, a focal pointsize, etc. The value of the tube current may include a value of tubecurrent of a first calibration point, a value of tube current of asecond calibration point. The first calibration point may include acalibration point of which the value of the tube current is within adefault current range (e.g., 30 mA to 300 mA). The second calibrationpoint may be a calibration point of which the value of the tube currentis outside the default range. The calibration points may includeinformation of the value of the tube current, the value of the filamentcurrent, the value of tube voltage, the focal point size, etc. In someembodiments, the first filament current calibration data maycorrespondingly include fourth filament current calibration data, thefifth filament current calibration data, and sixth filament currentcalibration data in FIG. 7 .

In 604, the process 600 may determine the second filament currentcalibration data corresponding to the second value of the tube voltage.The determination operation of the second filament current calibrationdata may be implemented by the calibration module 410. The second valueof the tube voltage may be not equal to the first value of tube voltagein step 602. The determination of the second filament currentcalibration data may be performed by using a method same as thatdescribed in step 602.

In 606, the process 600 may determine the third filament currentcalibration data corresponding to the third value of the tube voltagebased on the first filament current calibration data and the secondfilament current calibration data. The operation of determining thethird filament current calibration data may be implemented by thecalibration module 410. The determination of the third filament currentcalibration data may be performed based on an interpolation algorithm(e.g., a linear interpolation algorithm). For example, filament currentcalibration data corresponding to tube voltage of 80 kV may bedetermined by using the linear interpolation algorithm based on thefilament current calibration data corresponding to the tube voltage of70 kV and the tube voltage of 100 kV.

It should be noted that the above description of the process 600 isprovided merely for illustration, and is not intended to limit the scopeof the present disclosure. It may be appreciated that for persons havingordinary skills in the art, after understanding the principle of thesystem, changes can be made on the process 600, and variousmodifications and changes in forms and details of the application ofperforming the above-mentioned control flow can be made withoutdeparting from the scope of the principle. For example, the order of thesteps may be adjusted, or some steps may be added or removed. Forexample, a step of determining seventh filament current calibration datacorresponding to a fourth tube voltage may be added between step 604 andstep 606. In step 606, the third filament current calibration datacorresponding to the third value of the tube voltage may be determinedbased on the first filament current calibration data, the secondfilament current calibration data, and the seventh filament currentcalibration data.

FIG. 7 illustrates a flowchart of an exemplary process 700 for X-raytube filament calibration according to some embodiments of the presentdisclosure. One or more operations in the process 700 may be implementedby the imaging control device 120. Specifically, in some embodiments,one or more operations in the process 700 may be implemented by thecalibration module 410. In some embodiments, step 602 and/or step 604 inFIG. 6 may be implemented by performing one or more operations in theprocess 700.

In 701, the process 700 may determine one or more first calibrationpoints corresponding to a value of tube voltage. Values of tube currentof the first calibration points may be in a first range. The first rangemay be a default range of a value of the tube current. The default rangemay be a data range designated by a user or may be a data rangecalculated by an imaging system. The default range may be a continuouscurrent range (e.g., from 30 mA to 300 mA), or a set of discrete currentvalues (e.g., a set of 30 mA, 60 mA, 120 mA, 200 mA, and 300 mA). Insome embodiments, the first calibration points may be default points inTable 1.

In 702, the process 700 may calibrate the first calibration points todetermine fourth filament current calibration data. In some embodiments,the default points may be calibrated according to the method shown inFIG. 8 to generate the fourth filament current calibration data. Forexample, in a case of focus point size 1 and tube voltage of 70 kV inTable 1, the calibration points corresponding to values of the tubecurrent of 30 mA, 60 mA, 12 mA, 200 mA, and 300 mA may be calibratedaccording to the method shown in FIG. 8 to generate the fourth filamentcurrent calibration data.

In 704, the process 700 may determine a corresponding relationshipbetween tube current and filament current based on the fourth filamentcurrent calibration data. The corresponding relationship may bedetermined by a data fitting technique. The data fitting technique mayinclude a linear fitting technique, a curve fitting technique, etc.Specifically, the curve fitting technique may include a least squaremethod.

Specifically, in some embodiments, the operation of determining thecorresponding relationship may be implemented by the data fitting unit411. The process 700 may determine the relationship between the filamentcurrent and the tube current by curve fitting based on the fourthfilament current calibration data.

In 706, the process 700 may determine one or more second calibrationpoints corresponding to the value of the tube voltage based on thecorresponding relationship between the tube current and the filamentcurrent. The second calibration point may correspond to a value of thetube current, a value of the filament current, a value of the tubevoltage, a focal point size, etc.

The values of the tube current of the second calibration points may beoutside the first range. For example, the first range may be from 30 mAto 300 mA, and the values of the tube current of the second calibrationpoints may be 20 mA. The second calibration points may be interpolationpoints and/or endpoints based on the values of the tube current of thesecond calibration points. The interpolation points may be one or morecalibration points corresponding to a value of the tube current in thesecond range and outside the first range. For example, as shown in Table1, the first range may be from 30 mA to 300 mA, and the correspondingsecond range may be from 8 mA to 25 mA or from 400 mA to 600 mA, so thatthe interpolation points may be calibration points corresponding to thetube current of which the values are 10 mA, 400 mA, 500 mA, and 600 mA.The endpoints may be a calibration point corresponding to a maximumand/or minimum value of the tube current in one or more calibrationpoints corresponding to the tube voltage. For example, as shown in Table1, if the values of the tube current corresponding to a focal point size1 and tube voltage of 70 kV are 6 mA, 10 mA, 400 mA, 500 mA, and 600 mA,the endpoints may be calibration points corresponding to values of thetube current of 6 mA and 600 mA.

Specifically, in some embodiments, the operation of determining thesecond calibration points may be implemented by the data fitting unit411. A value of the filament current corresponding to a value of thetube current at a specific value of the tube voltage and focal pointsize may be determined based on a result of the data fitting (e.g., afitting function of the relationship between the filament current andthe tube current). A second calibration point may be determined based onthe value of the tube current and the value of the filament current.

In 708, the process 700 may determine whether the values of the tubecurrent corresponding to the second calibration points are satisfiedwith a preset condition. The preset condition may be that the values ofthe tube current are equal to or smaller than a second threshold of thetube current, or equal to or larger than a third threshold of the tubecurrent. The second threshold of the tube current may be a minimum valueof the tube current. The third threshold of the tube current may be amaximum value of the tube current. If the values of the tube currentexceed the maximum value, overcurrent may exist. The second threshold ofthe tube current and the third threshold of the tube current may be adefault setting of the imaging system 100, an empirical value, a valueof the tube current set by a user (e.g., a doctor), etc. If the valuesof the tube current corresponding to the second calibration points aresatisfied with the preset condition, the process 700 may proceed to step712. If the values of the tube current corresponding to the secondcalibration points are not satisfied with the preset condition, theprocess 700 may proceed to step 714.

In 712, the process 700 may determine fifth filament current calibrationdata of the second calibration points based on the correspondingrelationship between the tube current and the filament current. Thesecond calibration points may be endpoints. The endpoints may includecalibration points at which a condition being equal to or smaller thanthe second threshold of the tube current or equal to or larger than thethird threshold of the tube current is satisfied. The fifth filamentcurrent calibration data may be determined by calculating the value ofthe tube current and the value of the filament current based on thecorresponding relationship between the tube current and the filamentcurrent. In some embodiments, in order to avoid overcurrent, the fittingresult may be directly determined to be the fifth filament currentcalibration data of the endpoints. For example, in a case of focal pointsize 1 and a value of tube voltage of 70 kV, the second calibrationpoints may be calibration points corresponding to values of the tubecurrent of 6 mA and 610 mA in Table 1. The fitting data corresponding tothe calibration points corresponding to the values of the tube currentof 6 mA and 610 mA may be taken as the fifth filament currentcalibration data.

In 714, the process 700 may calibrate the second calibration points todetermine sixth filament current calibration data of the secondcalibration points. The second calibration points may be interpolationpoints. The interpolation points may be calibration points which are notsatisfied with the condition in step 708. In some embodiments, in step714, the interpolation points may be calibrated by using the methodshown in FIG. 8 to determine the sixth filament current calibrationdata. For example, in a case of focal point size 1 and tube voltage of70 kV in Table 1, the calibration points corresponding to values of thetube current of 10 mA, 400 mA, 500 mA, and 600 mA may be calibratedaccording to the method shown in FIG. 8 to generate the sixth filamentcurrent calibration data.

In some embodiments, the steps 708 through 714 may be performedcyclically until all the second calibration points are determined. Thefilament current calibration data of a plurality of calibration points(e.g., the first calibration points, the second calibration points)corresponding tube voltage may be generated based on the fourth filamentcurrent calibration data determined in step 702, the fifth filamentcurrent calibration data determined in step 712, and the sixth filamentcurrent calibration data determined in step 714.

FIG. 8 illustrates a flowchart of an exemplary process 800 for filamentcurrent calibration data generation corresponding to a calibration pointaccording to some embodiments of the present disclosure. One or moreoperations in the process 800 may be implemented by the imaging controldevice 120. Specifically, in some embodiments, one or more operations inthe process 800 may be implemented by the calibration module 410. Insome embodiments, step 702 and step 714 in FIG. 7 may be implemented byperforming one or more operations in the process 800.

In 802, the process 800 may obtain a preset value of tube current and avalue of filament current corresponding to a calibration point. Thepreset value of the tube current and the preset value of the filamentcurrent corresponding to the calibration point may be obtained by theI/O module 430, the storage module 440, etc.

The calibration point may be a known calibration point. For example, thecalibration point may be a factory setting parameter. The calibrationpoint may be a calibration point obtained by calculation. For example,the calibration point may be a calibration point obtained by a datafitting technique. The calibration point may be a calibration pointcorresponding to a value of tube current in any range. For example, thecalibration point may be the first calibration points and/or the secondcalibration points in FIG. 7 .

In 804, the process 800 may assign an initial value to an iterationnumber. The initial value may be 0 or an integer equal to or larger than0. The iteration number may represent the times that the preset value ofthe tube current is updated to an actual value of the tube current.

In 806, the process 800 may determine whether the iteration number islarger than an iteration-number threshold. The iteration-numberthreshold may be a number calculated by the imaging system 100, or avalue set by a user, etc. If the iteration number is larger than theiteration-number threshold, the process 800 may proceed to step 808. Ifthe iteration number is not larger than the iteration-number threshold,the process 800 may proceed to step 810.

In 808, the process 800 may report an error. The reporting form of theerror may be a literal form, a voice form, an image form, etc. The errormay be sent to the terminal 130 or displayed on the display 140.

In 810, the process 800 may perform an emission operation based on thepreset value of the tube current and the value of the filament current.The emission operation may be implemented by the imaging device 110. Insome embodiments, the emission operation process may include making afilament preheating plan.

In 812, the process 800 may determine an actual value of the tubecurrent during the emission operation. The actual value of the tubecurrent may be a value of the tube current at a specific time (e.g., atime point, a time segment), or a value obtained by calculation based onvalues of the tube current at a plurality of times during the emissionoperation (e.g., an average of the values of the tube current at aplurality of times). The emission operation may be one emissionoperation or a plurality of emission operations. For example, during anemission operation, a value of the tube current at time T1 is a firstvalue (e.g., mA1), a value of the tube current at time T2 is a secondvalue (e.g., mA2), and a value of the tube current at time T3 is a thirdvalue (e.g., mA3). In some embodiments, the actual value of the tubecurrent may be the first value (mA1), the second value (mA2), and/or thethird value (mA3). In some embodiments, the actual value of the tubecurrent may also be an average of the first value (mA1), the secondvalue (mA2), and the third value (mA3).

In 814, the process 800 may determine whether a difference between theactual value of the tube current and the preset value of the tubecurrent is satisfied with a preset condition. The preset condition mayinclude that the difference is larger than a first threshold and smallerthan a second threshold. If the difference is satisfied with thecondition, the process 800 may proceed to step 820. If the difference isnot satisfied with the condition, the process 800 may proceed to step816. The first threshold and the second threshold may be valuescalculated by the imaging system 100, and may also be values set by auser. The first threshold and the second threshold each may be anyvalue. The absolute values of the first threshold and the secondthreshold may be equal or not. For example, the first threshold may be−1 mA, and the second threshold may be 1 mA. As another example, thefirst threshold may be −1 mA, and the second threshold may be 2 mA.

In 820, the process 800 may generate filament current calibration dataof the calibration point. The filament current calibration data of thecalibration point may include the calibrated value of the filamentcurrent, the calibrated value of the tube current, the value of the tubevoltage and the focal point size corresponding to the calibration point.

In 816, the process 800 may update the preset value of the tube currentto the actual value of the tube current.

In 818, the process 800 may update the iteration number. For example,the process 800 may update the iteration number according to anincrement. The increment may be 1 or any other value. For example, theiteration number N may be updated to N+1, and N may be any value. Afterupdating the iteration number, the process 800 may proceed to step 806.If the iteration number does not exceed an iteration-number threshold,the process 800 may repeat operations of steps 806 through 818.

It should be noted that the above description of the generation of thefilament current calibration data of the calibration point is providedmerely for illustration, and is not intended to limit the scope of thepresent disclosure. It may be appreciated that for persons havingordinary skills in the art, after understanding the principle of thepresent invention, changes can be made on the method for generating thefilament current calibration data of the calibration point, and variousmodifications and changes in forms and details of the application ofperforming the above control flow can be made without departing from thescope of the principle. For example, the order of the steps may beadjusted, or some steps may be added or removed. As another example, aratio of the actual value of the tube current to the preset value of thetube current may be calculated in step 814. Whether the preset value ofthe tube current is updated to the actual value of the tube current maybe determined based on the ratio.

FIG. 9 illustrates a flowchart of an exemplary process 900 for X-raytube preheating plan generation according to some embodiments of thepresent disclosure. One or more operations in the process 900 may beimplemented by the imaging control device 120. Specifically, in someembodiments, one or more operations in the process 900 may beimplemented by the preheating module 420. In some embodiments, step 520in FIG. 5 may be implemented by performing one or more operations in theprocess 900.

In 910, the process 900 may determine a value of tube voltage, a valueof tube current and a start time for emission based on an emission plan.The emission plan may be obtained from the I/O module 430, the storagemodule 440, or the database 150. The emission plan may include the valueof the tube voltage, the value of the tube current and the start timefor emission.

In 920, the process 900 may determine a start time for preheating. Thedetermination of the start time for preheating may be implemented by thepreheating time determination unit 423. The start time for preheatingmay be the time when the high voltage generator 320 starts to perform afilament preheating operation. The start time for preheating may be thetime of obtaining the emission plan. For example, if the time ofobtaining the emission plan is 10:00 PM, the start time for preheatingmay be 10:00 PM. The start time for preheating may be the current timeof the system. The start time for preheating may also be a timeindependent of the current time of the system.

In 930, the process 900 may determine a time length of preheating of afilament based on the start time for emission and the start time forpreheating. The determination of the time length of preheating of thefilament may be implemented by the preheating time determination unit423. The time length of preheating of the filament may be a timedifference between the start time for preheating and the start time foremission. For example, the start time for preheating may be 09:40 PM andthe start time for emission may be 09:45 PM, the time length ofpreheating may be 5 minutes.

In 940, the process 900 may establish a heating model. The heating modelmay include a corresponding relationship of a value of the tube voltage,a value of the tube current, a time length of preheating of a filament,and filament preheating current. The filament preheating current maycorrespond to filament current in a filament preheating process. Theheating model may be a data table, a multivariate function, and a graph(e.g., a straight line).

In some embodiments, the heating model may be a look-up table. Thelook-up table may include a corresponding relationship of the value ofthe tube current, the time length of preheating of the filament, and thefilament preheating current at given tube voltage. The look-up table mayinclude a value of the tube current, a time length of a first standardpreheating, a time length of a second standard preheating, first currentof the filament preheating, second current of the filament preheating,and third current of the filament preheating. The time length of thesecond standard preheating may be larger than the time length of thefirst standard preheating. The time length of the first standardpreheating and the time length of the second standard preheating may bedefault values of the imaging system 100. If the time length ofpreheating of the filament is smaller than the time length of the firststandard preheating, the filament preheating current in the preheatingplan may be determined as a value of a first filament preheating currentbased on the value of the tube current. If the time length of preheatingof the filament is larger than or equal to the time length of the firststandard preheating and smaller than the time length of the secondstandard preheating, the filament preheating current in the preheatingplan may be determined as a value of a second filament preheatingcurrent based on the value of the tube current. If the time length ofpreheating of the filament is larger than or equal to the time length ofthe second standard preheating, the filament preheating current in thepreheating plan may be determined as a value of a third filamentpreheating current based on the value of the tube current.

For example, Table 2 shows a look-up table corresponding to tube voltageof 80 kV. Specifically, Table 2 shows the corresponding relationship ofthe tube current, the time length of preheating of the filament, and thefilament preheating current at tube voltage of 80 kV, wherein, t1 is thetime length of the first standard preheating, and t2 is the time lengthof the second standard preheating which is larger than the time lengthof the first standard preheating. t1 and t2 may be default values set bythe imaging system 100. As shown in Table 2, taking tube current of 10mA as an example, when the time length of preheating of the filament issmaller than t1, the filament preheating current is 3.3732 A (the valueof the first filament preheating current); when the time length ofpreheating of the filament is larger than or equal to t1 and smallerthan t2, the filament preheating current is 3.3232 A (the value of thesecond filament preheating current); and when the time length ofpreheating of the filament is larger than or equal to t2, the filamentpreheating current is 3.2589 A (the value of the third filamentpreheating current). For a definite value of the tube voltage and adefinite value of the tube current, the value of the filament preheatingcurrent may decrease as the increasing of the preheating time length.

TABLE 2 Preheating Plan Look-up Table at Tube Voltage of 80 Kv. TimeLength of Preheating of a filament <t1 t1 t2 First Filament SecondFilament Third Filament Preheating Preheating Preheating Tube CurrentCurrent (A) Current (A) Current (A)  10 mA 3.3732 3.3232 3.2589  20 mA3.5315 3.4815 3.432   30 mA 3.6444 3.5944 3.5413  40 mA 3.7335 3.68353.6168  50 mA 3.8077 3.7577 3.6916  60 mA 3.8715 3.8215 3.7703  70 mA3.9278 3.8778 3.8195  80 mA 3.9783 3.9283 3.8742  90 mA 4.0241 3.97413.9115 100 mA 4.0662 4.0162 3.9441 110 mA 4.1051 4.0551 4.0018 120 mA4.1413 4.0913 4.0324 . . . . . . . . . . . .

In 950, the process 900 may generate a filament preheating plan based onthe value of the tube voltage, the value of the tube current, the timelength of preheating of the filament, and the heating model. Theoperation of generating the filament preheating plan may be implementedby the preheating plan generation unit 425. The filament preheating planmay include information such as a value of the filament preheatingcurrent, and time information corresponding to the value of the filamentpreheating current. The time information may include information relatedto the time such as one or more time points (e.g., a start time, an endtime, a specific moment (e.g., 9 PM)), and time periods (e.g., 3seconds, 1 to 2 seconds). For example, the filament preheating plan maybe that the preheating is performed with filament preheating current of10 mA and the preheating time length is 3 seconds. As another example,the filament preheating plan may be that the preheating is performedwith filament preheating currents of 10 mA and 5 mA, specifically thepreheating is performed with filament preheating current of 10 mA in thefirst to second seconds, and the preheating is performed with filamentpreheating current of 5 mA in the second to third seconds.

In some embodiments, as shown in Table 2, when the time length ofpreheating of the filament is smaller than t1, the filament preheatingcurrent is the value of the first filament preheating current; when thetime length of preheating of the filament is larger than or equal to t1and smaller than t2, the filament preheating current is the value of thesecond filament preheating current; and when the time length ofpreheating of the filament is larger than t2, the filament preheatingcurrent is the value of the third filament preheating current.

In some embodiments, the time length of preheating of the filament maybe same as an actual time length of heating of the filament. In someembodiments, the actual time length of heating of the filament may beset to a fixed value or a variable value based on different time lengthsof preheating. For example, as shown in Table 2, when the time length ofpreheating of the filament is smaller than t1, the filament preheatingcurrent is the value of the first filament preheating current, theactual time length of heating of the filament may be the time length ofpreheating; when the time length of preheating of the filament is largerthan or equal to t1 and smaller than t2, the filament preheating currentis the value of the second filament preheating current, the actual timelength of heating of the filament may be t1; and when the time length ofpreheating of the filament is larger than t2, the filament preheatingcurrent is the value of the third filament preheating current, theactual time length of heating of the filament may be t2.

It should be noted that the above description of the process forgenerating the X-ray tube preheating plan is provided merely forillustration, and is not intended to limit the scope of the presentdisclosure. It may be appreciated that for persons having ordinaryskills in the art, after understanding the principle of the system,various modifications and changes in forms and details can be made onthe specific ways and steps of the process 900 of generating the X-raytube preheating plan, however, these modifications and changes may notdepart from the scope of the claims of the present disclosure. Forexample, in Table 2, the segment number of the time length of preheatingof the filament and the filament preheating current may be 3 as shown inTable 2, and may also be 4, 5, etc.

FIG. 10 illustrates a flowchart of an exemplary process 1000 for X-raytube preheating plan generation according to some embodiments of thepresent disclosure. One or more operations in the process 1000 may beimplemented by the imaging control device 120. In some embodiments, step530 in FIG. 5 may be implemented by performing one or more operations inthe process 1000.

In 1010, the process 1000 may scan an instruction of an X-ray loadingplan. The operation of scanning the X-ray loading plan may beimplemented by the master processor 1212. The imaging system 100 mayperform an emission operation based on the instruction of the X-rayloading plan.

In 1020, the process 1000 may determine whether the instruction of theX-ray loading plan is received. The operation of determining whether theinstruction of the X-ray loading plan is received may be implemented bythe master processor 1212. If the instruction of the X-ray loading planis received, the process 1000 may proceed to step 1050. If theinstruction of the X-ray loading plan is not received, the process mayproceed to step 1030.

In 1050, the process 1000 may perform the instruction of the X-rayloading plan. The operation of performing the instruction of the X-rayloading plan may be performing an emission operation according to anemission plan.

In 1030, the process 1000 may determine a time length beyond a timelength of preheating. The operation of determining the time lengthbeyond the time length of preheating may be implemented by thepreheating module 420.

In 1040, the process 1000 may update a filament preheating plan based onthe time length beyond the time length of preheating. The operation ofupdating the filament preheating plan may be implemented by thepreheating module 420. The operation of updating the filament preheatingplan may include the determination of information such as one or morefilament preheating current, and time information corresponding to theone or more filament preheating current. The filament preheating planmay be updated based on a heating model. The heating model may include acorresponding relationship of a time length of preheating, a time lengthbeyond the time length of preheating, tube current, filament preheatingcurrent, etc.

In some embodiments, after the circuit completes the preheatingaccording to an original preheating plan, the master processor may stillnot receive the instruction of the X-ray loading plan, and the emissionis still not started. To ensure that the filament temperature will notexceed a target value due to long-time heating, the filament preheatingmay be controlled by using a method of changing the values of thefilament preheating current in different time segments, and thusobtaining good tube current performance.

In some embodiments, the filament preheating plan may be updated by afunctional operation. For example, information of the filamentpreheating current and corresponding time information in the time lengthbeyond the time length of preheating may be calculated according to thetime length of preheating and the time length beyond the time length ofpreheating.

In the heating model, the time length beyond the time length ofpreheating may include a first timeout length (e.g., Δt1) and a secondtimeout length (e.g., Δt2). The heating model may include first timeoutfilament preheating current corresponding to the first timeout lengthand second timeout filament preheating current corresponding to thesecond timeout length. If the preheating time ends and the instructionof the X-ray loading plan is not received, the preheating may beperformed in the range of the first timeout length with the firsttimeout filament preheating current. If the second timeout length endsand the instruction of the X-ray loading plan is not received, thepreheating may be performed in the range of the second timeout lengthwith the second timeout filament preheating current. Similarly, if theN-th timeout length ends and the instruction of the X-ray loading planis not received, the preheating may be performed in the range of theN-th timeout length with the N-th timeout filament preheating current.In some embodiments, after the second timeout length ends, if theinstruction of the X-ray loading plan is not received, the filamentpreheating current may be maintained as the second timeout filamentpreheating current.

In some embodiments, the filament preheating plan may be updated via thelook-up Table 3. For example, Table 3 shows the correspondingrelationship of the tube current, the time length of preheating, thetime length beyond the time length of preheating, and the filamentpreheating current at tube voltage of 80 kV. Wherein, t1 is a timelength of preheating, the value of the filament preheating currentcorresponding to the time length of preheating is a value of a fourthcurrent of the filament preheating. After the time length of preheatingt1 ends, if the instruction of the X-ray loading plan is not received, atime length Δt1 beyond the time length of preheating and a value offirst timeout filament preheating current corresponding to the timelength Δt1 beyond the time length of preheating may be determined. Afterthe time lengths of t1 and Δt1 end if the instruction of the X-rayloading plan is not received, a time length Δt2 beyond the time lengthof preheating and a value of second timeout filament preheating currentcorresponding to the time length Δt2 beyond the time length ofpreheating may be determined. For convenience, the filament preheatingcurrent after Δt2 may be maintained as the value of the second timeoutfilament preheating current. In Table 3, n in Δtn is an integer greaterthan 2.

TABLE 3 Preheating Plan Updating Look-up Table at Tube Voltage of 80 kV.Time Length beyond the Time Length Time Length of Preheating ofPreheating Δt1 Δt2~Δtn t1 Value of the Value of the Value of the FirstTimeout Second Timeout Tube Voltage Fourth Filament Filament Filament 80kV Preheating Preheating Preheating Tube Current Current (A) Current (A)Current (A)  10 mA 3.3232 3.2732 3.2446  20 mA 3.4815 3.4365 3.4275  30mA 3.5944 3.5494 3.5332  40 mA 3.6835 3.6335 3.6001  50 mA 3.7577 3.70273.6805  60 mA 3.8215 3.7715 3.7691  70 mA 3.8778 3.8228 3.8162  80 mA3.9283 3.8783 3.8701  90 mA 3.9741 3.9191 3.9039 100 mA 4.0162 3.95623.932  110 mA 4.0551 4.0061 3.9975 120 mA 4.0913 4.0368 4.028  . . . . .. . . . . . .

It should be noted that the above description of the process forgenerating the X-ray tube preheating plan is provided merely forillustration, and is not intended to limit the scope of the presentdisclosure. It may be appreciated that for persons having ordinaryskills in the art, after understanding the principle of the system,various modifications and changes in forms and details can be made onthe specific ways and steps of the process 1000, however, thesemodifications and changes may not depart from the scope of the claims ofthe present disclosure. For example, in Table 3, the filament preheatingcurrent after Δt2 may be variable.

FIG. 11 illustrates a flowchart of an exemplary process 1100 forfilament preheating plan generation according to some embodiments of thepresent disclosure. One or more operations in the process 1100 may beimplemented by the imaging control device 120. In some embodiments, step550 in FIG. 5 may be implemented by performing one or more operations inthe process 1100.

In 1110, the process 1100 may determine a value of tube voltage, a valueof tube current and a start time for emission based on an emission plan.The operation of determining the value of the tube voltage, the value ofthe tube current and the start time for emission may be implemented bythe preheating module 420. The emission plan may be obtained from theI/O module 430, the storage module 440, or the database 150. Theemission plan may include the value of the tube voltage, the value ofthe tube current and the start time for emission.

In 1120, the process 1100 may determine a start time for preheating. Theoperation of determining the start time for preheating may beimplemented by the preheating module 420. The start time for preheatingmay be the time of starting to perform a filament preheating operationby the high voltage generator 320.

In 1130, the process 1100 may determine a time length of preheating of afilament based on the start time for emission and the start time forpreheating. The operation of determining the time length of preheatingof the filament may be implemented by the preheating module 420. Thetime length of preheating of the filament may be a time interval betweenthe start time for preheating and the start time for emission. Forexample, if the start time for preheating is 09:40 PM and the start timefor emission is 09:45 PM, the time length of preheating of the filamentmay be 5 minutes.

In 1140, the process 1100 may establish a heating model. The operationof determining the heating model may be implemented by the preheatingmodule 420. The heating model may include the corresponding relationshipof tube voltage, tube current, a time length of preheating of afilament, a filament temperature, filament preheating current, etc. Thefilament preheating current may correspond to filament current during afilament preheating stage. The heating model may be presented in formsof a data table or a function. According to the data table, the process1100 may determine filament preheating current corresponding to the tubevoltage, the tube current, the time length of preheating of thefilament, and the filament temperature. According to the function, theprocess 1100 may determine filament preheating current corresponding tothe tube voltage, the tube current, the time length of preheating of thefilament, and the filament temperature.

In 1150, the process 1100 may determine a filament temperature. Theoperation of determining the filament temperature may be implemented bythe preheating module 420. The filament temperature may be an initialvalue of the filament temperature when the process 1100 initiates. Theinitial value of the filament temperature may be a result of theprevious emission. The filament temperature may be obtained from acomponent or a device (e.g., a thermometer) in the imaging system. Thefilament temperature may also be determined by the calculation of theimaging system 100. In some embodiments, the process 1100 may determinean equivalent description value of the filament temperature. Theequivalent description value may describe the thermionic emissioncapability of the filament. The equivalent description value of thefilament temperature may be a result of the previous emission.

According to the previous emission, the process 1100 may determine theinitial value of the filament temperature or the equivalent descriptionvalue of the filament temperature. According to the previous emission,tube voltage of the previous emission, a value of the tube current ofthe previous emission, and an end time for the previous emission may bedetermined. A time interval may be determined based on the end time forthe previous emission and the start time for emission. The time intervalmay be a time difference between the end time for the previous emissionand the start time for emission. The initial value of the filamenttemperature or the equivalent description value of the filamenttemperature may be determined according to the tube voltage of theprevious emission, the value of the tube current of the previousemission, and the time interval.

In some embodiments, the process 1100 may determine the initial value ofthe filament temperature or the equivalent description value of thefilament temperature based on a filament temperature model. The filamenttemperature model may represent the corresponding relationship of a timeinterval between two times of emission, tube current, and a filamenttemperature. The filament temperature model may exist in the form of afilament radiation table. The filament radiation table may include thecorresponding relationship of the tube voltage of the previous emission,the tube current of the previous emission, the time interval between twotimes of emission, one or more time ranges, and one or more filamenttemperatures. The one or more time ranges may include a first time range(e.g., 0 to t1), a second time range (e.g., t1 to t2), a third timerange (e.g., t2 to t3), and a fourth time range (e.g., greater than t3).In the radiation table, a filament temperature corresponding todifferent values of the tube current and time ranges may be stored. Thefirst time range, the second time range, the third time range, and thefourth time range may be time ranges segmented by a first time point(e.g., a time point t1), a second time point (e.g., a time point t2),and a third time point (e.g., a time point t3). The first time point,the second time point, and the third time point may be obtained bycalculation of the imaging system or determined by a user (e.g., a valuedetermined by a user based on experience). The filament temperature maybe determined by looking up the filament radiation table according tothe time interval between the two times of emission, and the tubecurrent of the previous emission.

For example, a filament radiation table corresponding to different timeintervals and tube currents as shown in Table 4 may be obtained from theheating model 1213. Table 4 shows the corresponding relationship of thetube current, the time interval, and the filament temperature at tubevoltage of 80 V As shown in Table 4, for a definite value of the tubevoltage and a definite value of the tube current, when the time intervalfalls into different time ranges (e.g., 0 to t1 (corresponding to tc1 inTable 4), t1 to t2 (corresponding to tc2 in Table 5), t2 to t3(corresponding to tc3 in Table 5)), corresponding filament temperaturemay be obtained (e.g., T3° C., T2° C., T1° C., 0° C.). For example, whenthe value of the tube current is 50 mA, if the time interval fallswithin the time range of t1 to t2, the corresponding filamenttemperature is 0° C. As another example, when the value of the tubecurrent is 200 mA, if the time interval falls within the time range oft1 to t2, the corresponding filament temperature is T1° C.

TABLE 4 Filament Radiation Table of different Time Intervals and TubeCurrent. Time Interval 0~t1 t1~t2 t2~t3 >t3 Tube Voltage FilamentFilament Filament Filament 80 kV Temperature Temperature TemperatureTemperature Tube Current (° C.) (° C.) (° C.) (° C.)  50 mA T1 0 0 0 100mA T2 0 0 0 150 mA T2 0 0 0 200 mA T2 T1 0 0 250 mA T2 T1 0 0 300 mA T3T1 T1 0 350 mA T3 T1 T1 0 400 mA T3 T2 T1 0 450 mA T3 T2 T1 0 500 mA T3T2 T2 0 550 mA T3 T2 T2 0 600 mA T3 T2 T2 0 . . . T3 T2 T2 0

In 1160, the process 1100 may generate a filament preheating plan basedon the value of the tube voltage, the value of the tube current, thetime length of preheating of the filament, the filament temperature, andthe heating model. The operation of generating the filament preheatingplan may be implemented by the preheating module 420. The filamentpreheating plan may include information such as filament preheatingcurrent, and time information corresponding to the filament preheatingcurrent.

In some embodiments, the heating model may exist in the form of a datatable. The data table may include tube voltage, a first standardpreheating time, a second standard preheating time, a value of the tubecurrent, a value of the filament preheating current, a filamenttemperature, etc. The second standard preheating time may be larger thanthe first standard preheating time. The filament temperature may includea first filament temperature, a second filament temperature, and a thirdfilament temperature. The first filament temperature, the secondfilament temperature, and the third filament temperature may bedetermined based on a filament temperature model. The process 1100 maydetermine filament preheating current based on the filament temperature,the value of the tube voltage, the value of the tube current, therelationship of the time length of preheating of the filament, the firststandard preheating time and the second standard preheating time, andthe heating model.

For example, the heating model may exist in the form of a look-up table.The look-up table may include the corresponding relationship of a timelength of preheating of a filament, tube voltage, a filamenttemperature, and tube current. The time length of preheating of thefilament may include a time length of a first standard preheating and atime length of a second standard preheating. The time length of thesecond standard preheating may be larger than the time length of thefirst standard preheating. The filament temperature may include a firstfilament temperature, a second filament temperature, and a thirdfilament temperature. In some embodiments, the filament temperature maybe determined in step 1150. The first filament temperature maycorrespond to a first range (e.g., tc1 (corresponding to the range of 0to t1 in table 4)), the second filament temperature may correspond to asecond range (e.g., tc2 (corresponding to the range of t1 to t2 in table4)), and the third filament temperature may correspond to a third range(e.g., tc3 (corresponding to the range of t2 to t3 in table 4)). Afilament preheating temperature may be determined via the look-up tablebased on the filament temperature, the value of the tube current, thevalue of the tube voltage and the time length of preheating of thefilament.

For example, Table 5 shows the corresponding relationship of tubecurrent, a time length of preheating of a filament, a filamenttemperature, and filament preheating current at tube voltage of 80 kV.Wherein, a t1 is a time length of a first standard preheating, a t2 is atime length of a second standard preheating larger than the time lengthof the first standard preheating, and t1 and t2 may be default valuesset by the imaging system 100. A tc1 is a first time range. A tc2 is asecond time range. A tc3 is a third time range. A T1 is a first filamenttemperature corresponding to the first time range. A T2 is a secondfilament temperature corresponding to the second time range. A T3 is athird filament temperature corresponding to the third time range. For adefinite value of the tube voltage, a definite value of the tubecurrent, a definite time length of preheating of the filament, and adefinite filament temperature, the corresponding filament preheatingcurrent may be determined via the look-up table 5. Taking tube currentof 10 mA as an example, when the time length of preheating of thefilament is smaller than t1 and the filament temperature is T1° C., thefilament preheating current corresponding to the time length ofpreheating may be determined to 3.17664 A via Table 5.

TABLE 5 Look-Up Table of the Time Length of Preheating of a filament andcorresponding Value of the Tube Current. Tube voltage Time length ofpreheating of a filament 80 kV <t1 t1 t2 Tube tc1 tc2 tc3 tc1 tc2 tc3tc1 tc2 tc3 current T1 T2 T3 T1 T2 T3 T1 T2 T3 (mA) Filament preheatingcurrent (A)  10 mA 3.17664 3.2232 3.3732 3.1672 3.2032 3.3232 3.115383.11226 3.2589  20 mA 3.33494 3.3815 3.5315 3.3255 3.3615 3.4815 3.288483.28536 3.432  30 mA 3.46422 3.5069 3.6444 3.4514 3.4844 3.5944 3.409743.40688 3.5413  40 mA 3.55332 3.596 3.7335 3.5405 3.5735 3.6835 3.485243.48238 3.6168  50 mA 3.62752 3.6702 3.8077 3.6147 3.6477 3.7577 3.560043.55718 3.6916  60 mA 3.6636 3.734 3.8715 3.6565 3.7115 3.8215 3.61853.6152 3.7703  70 mA 3.7199 3.7903 3.9278 3.7128 3.7678 3.8778 3.66773.6644 3.8195  80 mA 3.7704 3.8408 3.9783 3.7633 3.8183 3.9283 3.72243.7191 3.8742  90 mA 3.80675 3.88035 4.0241 3.8016 3.8591 3.9741 3.75283.74935 3.9115 100 mA 3.84885 3.92245 4.0662 3.8437 3.9012 4.0162 3.78543.78195 3.9441 110 mA 3.88775 3.96135 4.1051 3.8826 3.9401 4.0551 3.84313.83965 4.0018 120 mA 3.92395 3.99755 4.1413 3.9188 3.9763 4.0913 3.87373.87025 4.0324 . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..

It should be noted that the above description of the process forgenerating the filament preheating plan is provided merely forillustration, and is not intended to limit the scope of the presentdisclosure. It may be appreciated that for persons having ordinaryskills in the art, after understanding the principle of the system,various modifications and changes in forms and details can be made onthe specific ways and steps of the process 1100, however, thesemodifications and changes may not depart from the scope of the claims ofthe present disclosure. For example, the process 1100 may first operatefor determining the filament temperature in step 1150, and then operatefor determining the heating model in step 1140.

FIG. 12 illustrates a flowchart of an exemplary process 1200 forfilament preheating plan generation according to some embodiments of thepresent disclosure. One or more operations in the process 1200 may beimplemented by the imaging control device 120. In some embodiments, step550 in FIG. 5 may be implemented by performing one or more operations inthe process 1200.

In 1210, the process 1200 may determine a time interval between an endtime for a first emission and a start time for a second emission. Theoperation of determining the time interval may be implemented by thepreheating module 420. The end time for the first emission and the starttime for the second emission may be determined based on a first emissionplan and a second emission plan. The first emission plan may include avalue of tube current of the first emission, a value of tube voltage ofthe first emission, a start time for the first emission, the end timefor the first emission, etc. The second emission plan may include avalue of the tube current of the second emission, a value of the tubevoltage of the second emission, the start time for the second emission,an end time for the second emission, etc. The time interval may be atime difference between the start time for the second emission and theend time for the first emission. For example, if the start time for thesecond emission is 10:30 PM, the end time for the first emission is10:00 PM, and the time interval is 30 minutes.

In 1220, the process 1200 may determine a difference between a value ofthe tube current of the first emission and a value of the tube currentof the second emission. The operation of determining the difference maybe implemented by the preheating module 420. In some embodiments, thedifference may be a current difference obtained by subtracting the valueof the tube current of the second emission from the value of the tubecurrent of the first emission. The value of the tube current of thesecond emission may be larger than, smaller than or equal to the valueof the tube current of the first emission.

In 1230, the process 1200 may determine a time length of preheatingbased on the difference and a heating model. The operation ofdetermining the time length of preheating may be implemented by thepreheating module 420. The heating model may include the correspondingrelationship of the difference, the tube voltage of the second emission,the time interval, filament preheating current, the time length ofpreheating, etc. The time length of preheating may be a time lengththrough which the value of the tube current of the first emission isincreased, decreased, or maintained at the value of the tube current ofthe second emission. The time length of preheating may be a time lengththrough which the filament temperature is changed to a second filamenttemperature.

In some embodiments, the heating model may be a look-up table in theheating model 1213. For example, the value of the tube current of thefirst emission is 10 mA, the value of the tube current of the secondemission is 20 mA, the difference is 10 mA. According to the look-uptable, a time length of preheating corresponding to the difference of 10mA may be determined.

In some embodiments, the heating model may be a function. The timelength of preheating may be determined by way of functional operationbased on the function, the difference, the time interval, etc. Thefilament preheating current may be filament current corresponding to avalue of the tube current which is increased, decreased, or maintainedat the value of the tube current of the first emission to the value ofthe tube current of the second emission. In some embodiments, thefilament current of which the value of the tube current of the firstemission is changed to the value of the tube current of the secondemission may be called a sustaining current.

In 1240, the process 1200 may determine whether the time interval issmaller than the time length of preheating. If the time interval issmaller than the time length of preheating, the process 1200 may proceedto step 1250. If the time interval is not smaller than the time lengthof preheating, the process 1200 may proceed to step 1260.

In 1250, the process 1200 may report an error. The operation ofreporting the error may be implemented by the preheating module 420. Theerror may include information such as the time interval, the time lengthof preheating, etc. The error may be sent to the terminal 130 ordisplayed on the display 140. For example, the value of the tube currentof the first emission is 10 mA, the value of the tube current of thesecond emission is 20 mA, the time interval is smaller than 1 second,but the corresponding time length of preheating of increasing the valueof the tube current from 10 mA to 20 mA is larger than 1 second. In thecondition of a time interval smaller than 1 second, the value of thetube current of the second emission cannot be increased from 10 mA to 20mA, and thus reporting an error. As another example, the value of thetube current of the first emission is 20 mA, the value of the tubecurrent of the second emission is 10 mA, the time interval is smallerthan 1 second, but the corresponding time length of preheating ofdecreasing the value of the tube current from 20 mA to 10 mA is largerthan 1 second. In the condition of a time interval smaller than 1second, the value of the tube current of the second emission cannot bedecreased from 20 mA to 10 mA, and thus reporting an error.

In 1260, the process 1200 may determine a filament preheating plan basedon the difference and the heating model. The filament preheating planmay include information such as filament preheating current, and timeinformation corresponding to the filament preheating current, etc.

Having thus described the basic concepts, it may be rather apparent tothose skilled in the art after reading this detailed disclosure that theforegoing detailed disclosure is intended to be presented by way ofexample only and is not limiting. Various alterations, improvements, andmodifications may occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested by this disclosure and arewithin the spirit and scope of the exemplary embodiments of thisdisclosure.

Moreover, certain terminology has been used to describe embodiments ofthe present disclosure. For example, the terms “one embodiment,” “anembodiment,” and/or “some embodiments” mean that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present disclosure.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the present disclosure.

Further, it will be appreciated by one skilled in the art, aspects ofthe present disclosure may be illustrated and described herein in any ofa number of patentable classes or context including any new and usefulprocess, machine, manufacture, or composition of matter, or any new anduseful improvement thereof. Accordingly, aspects of the presentdisclosure may be implemented entirely hardware, entirely software(including firmware, resident software, micro-code) or combiningsoftware and hardware implementation that may all generally be referredto herein as a “block,” “module,” “module,” “unit,” “component,” or“system.” Furthermore, aspects of the present disclosure may take theform of a computer program product embodied in one or more computerreadable media having computer readable program code embodied thereon.

A computer-readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including electro-magnetic, optical, or thelike, or any suitable combination thereof. A computer-readable signalmedium may be any computer-readable medium that is not acomputer-readable storage medium and that may communicate, propagate, ortransport a program for use by or in connection with an instructionexecution system, apparatus, or device. Program code embodied on acomputer-readable signal medium may be transmitted using any appropriatemedium, including wireless, wireline, optical fiber cable, RF, or thelike, or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object-oriented programming languagesuch as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB. NET,Python or the like, conventional procedural programming languages, suchas the “C” programming language, Visual Basic, Fortran 2003, Perl, COBOL2002, PHP, ABAP, dynamic programming languages such as Python, Ruby, andGroovy, or other programming languages. The program code may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider) or in a cloud computing environment or offered as aservice such as a Software as a Service (SaaS).

Furthermore, the recited order of processing elements or sequences, orthe use of numbers, letters, or other designations, therefore, is notintended to limit the claimed processes and methods to any order exceptas may be specified in the claims. Although the above disclosurediscusses through various examples what is currently considered to be avariety of useful embodiments of the disclosure, it is to be understoodthat such detail is solely for that purpose and that the appended claimsare not limited to the disclosed embodiments, but, on the contrary, areintended to cover modifications and equivalent arrangements that arewithin the spirit and scope of the disclosed embodiments. For example,although the implementation of various components described above may beembodied in a hardware device, it may also be implemented as a softwareonly solution—e.g., an installation on an existing server or mobiledevice.

Similarly, it should be appreciated that in the foregoing description ofembodiments of the present disclosure, various features are sometimesgrouped together in a single embodiment, figure, or description thereofto streamline the disclosure aiding in the understanding of one or moreof the various inventive embodiments. This method of disclosure,however, is not to be interpreted as reflecting an intention that theclaimed subject matter requires more features than are expressly recitedin each claim. Rather, inventive embodiments lie in less than allfeatures of a single foregoing disclosed embodiment.

In some embodiments, the numbers expressing quantities of ingredients,properties such as molecular weight, reaction conditions, and so forth,used to describe and claim certain embodiments of the application are tobe understood as being modified in some instances by the term “about,”“approximate,” or “substantially.” For example, “about,” “approximate,”or “substantially” may indicate ±20% variation of the value itdescribes, unless otherwise stated. Accordingly, in some embodiments,the numerical parameters set forth in the written description andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by a particular embodiment. Insome embodiments, the numerical parameters should be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of some embodiments of theapplication are approximations, the numerical values set forth in thespecific examples are reported as precisely as practicable.

Each of the patents, patent applications, publications of patentapplications, and other material, such as articles, books,specifications, publications, documents, things, and/or the like,referenced herein is hereby incorporated herein by this reference in itsentirety for all purposes, excepting any prosecution file historyassociated with same, any of same that is inconsistent with or inconflict with the present document, or any of same that may have alimiting affect as to the broadest scope of the claims now or laterassociated with the present document. By way of example, should there beany inconsistency or conflict between the description, definition,and/or the use of a term associated with any of the incorporatedmaterial and that associated with the present document, the description,definition, and/or the use of the term in the present document shallprevail.

In closing, it is to be understood that the embodiments of theapplication disclosed herein are illustrative of the principles of theembodiments of the application. Other modifications that may be employedmay be within the scope of the application. Thus, by way of example, butnot of limitation, alternative configurations of the embodiments of theapplication may be utilized in accordance with the teachings herein.Accordingly, embodiments of the present application are not limited tothat precisely as shown and described.

1-20. (canceled)
 21. A method for preheating a filament of an X-raytube, comprising: obtaining a first emission plan and a second emissionplan; determining, based on the first emission plan and the secondemission plan, a filament temperature, the filament temperature being aresult of a previous emission corresponding to the first emission plan;obtaining at least one of a value of a tube voltage, a value of a tubecurrent, or a time length for performing a filament preheating plancorresponding to the second emission plan; determining, based on thefilament temperature, and at least one of the value of the tube voltage,the value of the tube current, or the time length, the filamentpreheating plan corresponding to the second emission plan; andperforming, based on the filament preheating plan, a filament-preheatingoperation.
 22. The method of claim 21, wherein the determining, based onthe first emission plan and the second emission plan, the filamenttemperature includes: determining a value of a tube voltage of the firstemission plan, a value of a tube current of the first emission plan, anend time for the first emission plan, and a start time for the secondemission plan; and determining, based on the value of the tube voltageof the first emission plan, the value of the tube current of the firstemission plan, the end time for the first emission plan, and the starttime for the second emission plan, the filament temperature.
 23. Themethod of claim 22, wherein determining, based on the value of the tubevoltage of the first emission plan, the value of the tube current of thefirst emission plan, the end time for the first emission plan, and thestart time for the second emission plan, the filament temperatureincludes: determining, based on the end time for the first emissionplan, and the start time for the second emission plan, a time intervalbetween the first emission plan and the second emission plan; obtaininga filament temperature model; and determining, based on the value of thetube voltage of the first emission plan, the value of the tube currentof the first emission plan, and the time interval, the filamenttemperature using the filament temperature model.
 24. The method ofclaim 23, wherein the filament temperature model includes acorresponding relationship between the filament temperature and a timeinterval at a value of the tube voltage and a value of the tube currentof the first emission plan.
 25. The method of claim 21, wherein thedetermining, based on the filament temperature and at least one of thevalue of the tube voltage, the value of the tube current, or the timelength, a filament preheating plan corresponding to the second emissionplan, includes: obtaining a heating model; and generating the filamentpreheating plan based on the filament temperature and at least one ofthe value of the tube voltage, the value of the tube current, or thetime length for performing the filament preheating plan using theheating model.
 26. The method of claim 25, wherein the heating modelincludes a corresponding relationship of the time length, the tubevoltage, the filament temperature, and the tube current.
 27. The methodof claim 25, wherein the time length for performing the filamentpreheating plan is determined based on a start time for performing thesecond emission plan and a start time for performing the filamentpreheating plan.
 28. The method of claim 25, wherein the time length forperforming the filament preheating plan is determined according tooperations including: determining a difference between a value of thetube current of the first emission plan and the value of the tubecurrent of the second emission plan; and determining the time lengthbased on the difference and a heating model, wherein the heating modelincludes a corresponding relationship of the difference, and the timelength.
 29. The method of claim 25, wherein the generating, based on thefilament temperature and at least one of the value of the tube voltage,the value of the tube current, or the time length, the filamentpreheating plan includes: determining a time interval between an endtime for the first emission plan, and a start time for the secondemission plan; determine whether the time interval is smaller than thetime length; and in response to determining that the time interval isnot smaller than the time length, generating the filament preheatingplan based on the filament temperature, the value of the tube voltage,the value of the tube current, a difference between a value of the tubecurrent of the first emission plan and the value of the tube current ofthe second emission plan using the heating model.
 30. The method ofclaim 25, wherein the generating, based on the filament temperature andat least one of the value of the tube voltage, the value of the tubecurrent, or the time length, the filament preheating plan includes:includes: determining a time interval between an end time for the firstemission plan, and a start time for the second emission plan; determinewhether the time interval is smaller than the time length; and inresponse to determining that the time interval is not smaller than thetime length of preheating, reporting an error.
 31. A system forpreheating a filament of an X-ray tube, comprising: a storage devicestoring a set of instructions; and one or more processors configured tocommunicate with the storage device, wherein when executing the set ofinstructions, the one or more processors are configured to cause thesystem to: obtaining a first emission plan and a second emission plan;determining, based on the first emission plan and the second emissionplan, a filament temperature, the filament temperature being a result ofa previous emission corresponding to the first emission plan; obtainingat least one of a value of a tube voltage, a value of a tube current, ora time length for performing a filament preheating plan corresponding tothe second emission plan; determining, based on the filament temperatureand at least one of the value of the tube voltage, the value of the tubecurrent, or the time length, the filament preheating plan correspondingto the second emission plan; and performing, based on the filamentpreheating plan, a filament-preheating operation.
 32. The system ofclaim 31, wherein the determining, based on the first emission plan andthe second emission plan, the filament temperature includes: determininga value of a tube voltage of the first emission plan, a value of a tubecurrent of the first emission plan, an end time for the first emissionplan, and a start time for the second emission plan; and determining,based on the value of the tube voltage of the first emission plan, thevalue of the tube current of the first emission plan, the end time forthe first emission plan, and the start time for the second emissionplan, the filament temperature.
 33. The system of claim 32, whereindetermining, based on the value of the tube voltage of the firstemission plan, the value of the tube current of the first emission plan,the end time for the first emission plan, and the start time for thesecond emission plan, the filament temperature includes: determining,based on the end time for the first emission plan, and the start timefor the second emission plan, a time interval between the first emissionplan and the second emission plan; obtaining a filament temperaturemodel; and determining, based on the value of the tube voltage of thefirst emission plan, the value of the tube current of the first emissionplan, and the time interval, the filament temperature using the filamenttemperature model.
 34. The system of claim 31, wherein the determining,based on the filament temperature and at least one of the value of thetube voltage, the value of the tube current, or the time length, afilament preheating plan corresponding to the second emission plan,includes: obtaining a heating model; and generating the filamentpreheating plan based on the filament temperature and at least one ofthe value of the tube voltage, the value of the tube current, or thetime length for performing the filament preheating plan using theheating model.
 35. The system of claim 34, wherein the heating modelincludes a corresponding relationship of the time length, the tubevoltage, the filament temperature, and the tube current.
 36. The systemof claim 34, wherein the time length for performing the filamentpreheating plan is determined based on a start time for performing thesecond emission plan and a start time for performing the filamentpreheating plan.
 37. The system of claim 34, wherein the time length forperforming the filament preheating plan is determined according tooperations including: determining a difference between a value of thetube current of the first emission plan and the value of the tubecurrent of the second emission plan; and determining the time lengthbased on the difference and a heating model, wherein the heating modelincludes a corresponding relationship of the difference, and the timelength.
 38. The system of claim 34, wherein the generating, based on thefilament temperature and at least one of the value of the tube voltage,the value of the tube current, or the time length, the filamentpreheating plan includes: determining a time interval between an endtime for the first emission plan, and a start time for the secondemission plan; determine whether the time interval is smaller than thetime length; and in response to determining that the time interval isnot smaller than the time length, generating the filament preheatingplan based on the filament temperature, the value of the tube voltage,the value of the tube current, a difference between a value of the tubecurrent of the first emission plan and the value of the tube current ofthe second emission plan using the heating model.
 39. The system ofclaim 34, wherein the generating, based on the filament temperature andat least one of the value of the tube voltage, the value of the tubecurrent, or the time length, the filament preheating plan includes:includes: determining a time interval between an end time for the firstemission plan, and a start time for the second emission plan; determinewhether the time interval is smaller than the time length; and inresponse to determining that the time interval is not smaller than thetime length of preheating, reporting an error.
 40. A non-transitorycomputer readable medium including executable instructions that, whenexecuted by at least one processor, cause the at least one processor toeffectuate a method comprising: obtaining a first emission plan and asecond emission plan; determining, based on the first emission plan andthe second emission plan, a filament temperature, the filamenttemperature being a result of a previous emission corresponding to thefirst emission plan; obtaining at least one of a value of a tubevoltage, a value of a tube current, or a time length for performing afilament preheating plan corresponding to the second emission plan;determining, based on the filament temperature and at least one of thevalue of the tube voltage, the value of the tube current, or the timelength, a filament preheating plan corresponding to the second emissionplan; and performing, based on the filament preheating plan, afilament-preheating operation.